A sensing device

Abstract

The present specification discloses a sensing device. The sensing device comprises a shell configured to generate vibration based on a sound signal, a sensing structure for converting a sound pressure signal into an electrical signal having a first resonant frequency; and a resonant system, the resonant system comprising a vibration pickup unit, the vibration pickup unit comprising an elastic diaphragm connected to the sensing structure and a mass block, a mass of a polymer material in the mass block being more than 80%; wherein the resonant system has a second resonant frequency for the sensing device, the second resonant frequency being lower than the first resonant frequency. The sensing device provided by the present specification has higher sensitivity in a specific frequency band compared to the sensing structure by adding the resonant system, achieving the purpose of stable output gain, and the mass block containing the polymer material can absorb external impact load, effectively reducing stress concentration at the connection between the elastic diaphragm and the shell or other components, and improving the stability of the sensing device.

Description

[0001] Priority Information

[0002] This application claims priority to Chinese Application No. 202110445739.3, filed April 23, 2021, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to electronic devices, and in particular, to a sensing device. BACKGROUND

[0004] A vibration sensor (e.g., a microphone) receives an external vibration signal, and due to resonance, the vibration signal will generate a larger amplitude near the resonance frequency of the vibration sensor. Therefore, the response of the vibration sensor to the external vibration will show a resonance peak in the frequency response curve near the resonance frequency, and the sensitivity is higher near the resonance frequency. However, for some sensors (e.g., a gas conduction microphone), the resonance frequency is large (e.g., more than 10,000 Hz), and when the frequency of the external sound signal is at a non-resonance frequency of the sensor, the sensitivity of the sensor is low. The sensitive area of the user to sound is relatively low in the frequency range of the sensor, and at this time, the low frequency range is much smaller than the resonance frequency of the sensor, so the sound signal picked up by the sensor for the sound in the sensitive frequency range of the human ear is small, and the sensitivity is too low. In addition, the mass block in the vibration sensor is fixed with the components of the vibration sensing structure through the elastic membrane, and the mass block and the elastic membrane can vibrate in response to the external vibration signal. The mass block is usually made of hard materials such as metal, and the hardness, stiffness, Young's modulus, and other parameters of the mass block and the elastic membrane differ too much, so that the connection between the elastic membrane and other components is prone to damage.

[0005] Therefore, it is desirable to provide a sensing device that can adjust the sensitivity of the device in a wider frequency range, while having stable output gain and high impact resistance reliability. SUMMARY

[0006] The embodiment of the present specification provides a sensing device. The sensing device comprises a shell configured to convert a sound signal into vibration, a sensing structure for converting the sound signal into an electric signal, the sensing structure having a first resonant frequency; and a resonant system, the resonant system comprising a vibration pickup unit, the vibration pickup unit comprising an elastic vibration diaphragm connected with the shell and a mass block, the mass block having a mass of more than 80% of a high polymer material; the elastic vibration diaphragm and the sensing structure form a first acoustic cavity, when the shell of the sensing device generates vibration, the elastic vibration diaphragm and the mass block generate vibration in response to the vibration of the shell of the sensing device, the vibration of the elastic vibration diaphragm causes the sound pressure of the first acoustic cavity to change, and the sensing structure converts the external sound signal into an electric signal based on the sound pressure change of the acoustic cavity; the resonant system has a second resonant frequency, and the second resonant frequency is lower than the first resonant frequency.

[0007] Compared with the prior art, the sensing device provided by the present specification has the following beneficial effects: (1) the sensing device adds a resonant system to the sensing structure, the resonant system provides a second resonant frequency, solves the problem that the resonant frequency of the sensing structure (for example, a air conduction microphone) is relatively high, and the sensitivity in a low frequency band (for example, a middle and low frequency band) is relatively low, so that the sensing device can also have relatively high sensitivity in a specific frequency band (for example, near the second resonant frequency) compared with the sensing structure, and the purpose of stable output gain is achieved; (2) the elastic property of the mass block of the high polymer material can absorb external impact load, effectively reduce the stress concentration at the connection between the elastic vibration diaphragm and the shell or other components, and reduce the possibility of damage of the sensing device due to external impact. BRIEF DESCRIPTION OF DRAWINGS

[0008] The present application will be further illustrated in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, wherein:

[0009] Figure 1A is a schematic diagram of an exemplary sensing structure provided according to some embodiments of the present specification;

[0010] Figure 1B is a structural diagram of an exemplary microphone provided according to some embodiments of the present specification;

[0011] Figure 1C is an exemplary structural schematic diagram of a sensing element of a bone conduction microphone provided according to some embodiments of the present specification;

[0012] Figure 2A is a mechanical equivalent schematic diagram of an exemplary sensing device provided according to some embodiments of the present specification;

[0013] Figure 2B is a schematic diagram of a liquid-filled sensing device according to some embodiments of the present specification;

[0014] Figure 3 is a schematic diagram of an equivalent vibration model of a vibration pickup according to some embodiments of the present specification;

[0015] Figure 4 is a schematic diagram of normalized displacement resonance curves of vibration pickups with different parameters according to some embodiments of the present specification;

[0016] Figure 5A is an exemplary frequency response curve of a sensing device according to some embodiments of the present specification;

[0017] Figure 5B is an exemplary frequency response curve of another sensing device according to some embodiments of the present specification;

[0018] Figure 6 is a structural schematic diagram of a sensing device according to some embodiments of the present specification;

[0019] Figure 7 is a structural schematic diagram of a sensing device with a multi-layer composite membrane structure according to some embodiments of the present specification;

[0020] Figure 8 is a structural schematic diagram of a sensing device according to some embodiments of the present specification;

[0021] Figure 9 is a cross-sectional view of a sensing device with a ring-shaped mass according to some embodiments of the present specification;

[0022] Figure 10 is a cross-sectional view of a sensing device with a rectangular cylindrical mass according to some embodiments of the present specification;

[0023] Figure 11 is a cross-sectional schematic diagram of a sensing device according to some embodiments of the present specification;

[0024] Figure 12 is a cross-sectional schematic diagram of a sensing device according to some embodiments of the present specification;

[0025] Figure 13 is a cross-sectional schematic diagram of a sensing device according to some embodiments of the present specification;

[0026] Figure 14 is a structural schematic diagram of a sensing device according to some embodiments of the present specification;

[0027] Figure 15is a structural schematic diagram of a sensing device including a first hole portion according to some embodiments of the present specification;

[0028] Figure 16 is Figure 15 is a cross-sectional schematic diagram of a sensing device according to some embodiments of the present specification;

[0029] Figure 17 is a cross-sectional schematic diagram of a sensing device according to some embodiments of the present specification;

[0030] Figure 18 is a structural schematic diagram of a sensing device including a plurality of resonant systems according to some embodiments of the present specification. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor. Unless it is obvious from the language environment or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0032] A sensing device is provided in the embodiments of the present specification. In some embodiments, the sensing device includes a sensing structure and a resonant system coupled with the sensing structure. Wherein, the sensing structure can be used to convert external signals (e.g., sound signals, vibration signals, pressure signals) into target signals (e.g., electrical signals). The sensing structure can have a first resonant frequency, which is related to the properties (e.g., shape, material, structure, etc.) of the sensing structure itself. The resonant system has a second resonant frequency, wherein the second resonant frequency can be lower than the first resonant frequency. In some embodiments, the sensing structure can be connected with a vibration pickup unit, which can include an elastic diaphragm and a mass block. The vibration pickup unit will affect the response of the sensing structure to external signals, forming a resonant system. In other embodiments, the sensing structure can be encapsulated in a cavity (e.g., a cavity surrounded by the sensing device housing) containing a liquid. The liquid and the gas (if any) reserved in the cavity will affect the response of the sensing structure to external signals, forming a resonant system.

[0033] In some embodiments, the relationship between the second resonant frequency and the first resonant frequency can be adjusted by adjusting the properties of the sensing structure and / or the resonant system itself, such as adjusting the viscosity of the liquid forming the resonant system, the material, or adjusting the structure, material, etc. of the pick-up unit, so that the second resonant frequency is lower than the first resonant frequency, thereby improving the sensitivity of the sensing device at a lower frequency band. In some embodiments, in order to improve the sensitivity of the sensing device at different frequency bands, the difference between the second resonant frequency and the first resonant frequency can be adjusted by adjusting the properties of the sensing structure and / or the resonant system itself, so that the difference is within the range of 200 Hz to 15000 Hz, thereby making the sensitivity of the sensing device significantly improved compared to the sensitivity of the sensing structure within the desired frequency band.

[0034] The sensing device in the embodiments of the present specification adds a resonant system to the sensing structure, which provides a second resonant frequency. When the frequency of the external signal is near the second resonant frequency, the sensing device also has a relatively high sensitivity, solving the problem that the first resonant frequency of the sensing structure (such as a gas guide microphone) is relatively high, and the sensitivity is relatively high only at the first resonant frequency, but relatively low in other frequency ranges (such as low and medium frequency bands). The sensing device can also have a relatively high sensitivity compared to the sensing structure within a specific frequency band (such as near the second resonant frequency), achieving the purpose of stabilizing the output gain.

[0035] In some embodiments, the resonant system can include a pick-up unit configured to generate vibrations in response to vibrations of the housing of the sensing device, the pick-up unit including an elastic diaphragm and a mass, the elastic diaphragm being connected to the housing of the sensing device through its peripheral side. In some embodiments, the mass of the high polymer material is more than 80%. The elastic properties of the mass of high polymer material can absorb external impact loads, thereby effectively reducing the stress concentration at the connection between the elastic diaphragm and the housing of the sensing structure, to reduce the possibility of damage to the sensing device due to external impact. In some embodiments, the mass and the elastic diaphragm can be made of the same high polymer material. In some embodiments, the mass and the elastic diaphragm can be made of high polymer material with a mass of more than 80%. When the mechanical parameters (such as Young's modulus, stiffness, etc.) of the mass made of high polymer material and the mechanical parameters of the elastic diaphragm are the same or close, the frequency response of the mass and the elastic diaphragm to the vibration signal is similar, which can further reduce the stress concentration problem at the connection between the elastic diaphragm and the housing during vibration.

[0036] The sensing device provided by the embodiments of the present specification and one or more components (such as the sensing structure, the resonant system) in the sensing device will be described in detail below with reference to the accompanying drawings.

[0037] Figure 1Ais a schematic diagram of an exemplary sensing structure provided according to some embodiments of the present specification. The sensing structure 100 can be used to convert a sound signal into an electrical signal and has a first resonant frequency. Specifically, the sensing structure 100 can generate a mechanical vibration signal based on the sound signal, which can be further converted into an electrical signal by a transducing component (e.g., a sensing element 120) of the sensing structure 100. In some embodiments, the sensing structure 100 can also generate a deformation and / or displacement based on an external signal other than the sound signal, such as a mechanical signal (e.g., pressure, mechanical vibration), an electrical signal, an optical signal, a thermal signal, etc. The deformation and / or displacement can be further converted into a target signal by the transducing component of the sensing structure 100. In some embodiments, the target signal can include, but is not limited to, one or more of an electrical signal, a mechanical signal (e.g., mechanical vibration), an acoustic signal (e.g., sound wave), an electrical signal, an optical signal, a thermal signal, etc. In some embodiments, the sensing structure 100 can be a microphone (e.g., an air conduction microphone or a bone conduction microphone), an accelerometer, a pressure sensing structure, a hydrophone, an energy harvester, a gyroscope, etc. An air conduction microphone refers to a microphone in which sound waves are conducted through air. A bone conduction microphone refers to a microphone in which sound waves are conducted in a mechanical vibration manner in a solid (e.g., bone). In some embodiments, the sensing structure 100 can also be a microphone that combines bone conduction and air conduction. For a microphone that combines bone conduction and air conduction, please refer to the description of Figure 6 and related description.

[0038] In some embodiments, the sensing structure 100 can include a housing 110 and a sensing element 120, in which the sensing element 120 is housed inside the housing 110. The housing 110 can be a regular or irregular three-dimensional structure with a cavity (i.e., hollow portion) inside, such as a hollow frame structure, including but not limited to a rectangular frame, a circular frame, a regular polygonal frame, etc., and any irregular shape. In some embodiments, the sensing element 120 can be located in the cavity of the housing 110 or at least partially suspended in the cavity of the housing 110. The sensing element 120 is used to convert an external signal into a target signal. Taking a bone conduction microphone (also known as a vibration sensor) as an example, the external signal is a mechanical vibration signal. In some embodiments, the sensing element 120 can include a vibration unit and a transducing unit. The vibration unit has a certain elasticity. For example, the vibration unit can be a vibrating rod (e.g., a cantilever beam), a diaphragm, a vibrating mass, etc. The vibration unit generates a deformation and / or displacement in response to the mechanical vibration signal. The transducing unit can convert the deformation and / or displacement into a target signal (e.g., an electrical signal). The transducing unit can include a piezoelectric transducer, a capacitive transducer, etc.

[0039] Figure 1B is a structural diagram of an exemplary microphone provided according to some embodiments of the present specification.

[0040] like Figure 1B As shown, microphone 140 may include a printed circuit board (PCB) 141, a housing 142, a sensor element 143, and a processor 144. In some embodiments, PCB 141 may be one or more of a phenolic paper PCB substrate, a composite PCB substrate, a fiberglass PCB substrate, a metal PCB substrate, a build-up multilayer PCB substrate, and the like. In some embodiments, PCB 141 may be a fiberglass PCB substrate with an FR-4 rating made of epoxy fiberglass cloth. Circuitry and other components of microphone 140 may be provided on PCB 141 (e.g., by laser etching, chemical etching, etc.). In some embodiments, PCB 141 may also be a flexible printed circuit board (FPC). In some embodiments, sensor element 143 and processor 144 are fixedly connected to PCB 141 via sensor element fixing adhesive 145 and processor fixing adhesive 146, respectively. In some embodiments, sensor element fixing adhesive 145 and / or processor fixing adhesive 146 may be conductive adhesives (e.g., conductive silver adhesive, copper powder conductive adhesive, nickel-carbon conductive adhesive, silver-copper conductive adhesive, etc.). In some embodiments, the conductive adhesive can be one or more of conductive glue, conductive film, conductive rubber ring, conductive tape, etc. The sensing element 143 and / or the processor 144 are electrically connected to other components via circuits provided on the PCB 141. The sensing element 143 and the processor 144 can be directly connected via a wire 147 (e.g., gold wire, copper wire, aluminum wire, etc.).

[0041] The housing 142 may be a regular or irregular three-dimensional structure having a cavity (i.e., a hollow portion) inside. For example, it may be a hollow frame structure, including but not limited to regular shapes such as a rectangular frame, a circular frame, a regular polygonal frame, and any irregular shape. The housing 142 is provided above the PCB 141 to seal the sensor element 143, the processor 144, and the PCB 141 and the circuits and other components disposed thereon. The housing 142 may be made of metal (e.g., stainless steel, copper, etc.), plastic (e.g., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and acrylonitrile-butadiene-styrene copolymer (ABS), etc.), composite materials (e.g., metal-based composite materials or non-metal-based composite materials), etc. For example, in some embodiments, the material used for the housing 142 is brass.

[0042] The sensing element 143 can convert an external vibration signal into an electrical signal. Taking a bone conduction microphone as an example, the sensing element 143 can include a base structure, a laminated structure, and a damping structure layer. In some embodiments, part or all of the laminated structure is connected to the base structure by a physical method. The "connection" described in this application can be understood as the connection between different parts of the same structure, or after separately preparing different components or structures, the independent components or structures are fixedly connected by welding, riveting, clamping, bolting, adhesive bonding, or the like, or in the preparation process, the first component or structure is deposited on the second component or structure by physical deposition (for example, physical vapor deposition) or chemical deposition (for example, chemical vapor deposition). In some embodiments, part or all of the laminated structure can be fixed to the upper surface or the lower surface of the base structure, and part of the laminated structure can also be fixed to the side wall of the base structure.

[0043] In some embodiments, the laminated structure can include a vibration unit and an acoustic transducing unit. The vibration unit refers to a part of the laminated structure that is prone to deformation under external force, and the vibration unit can be used to transmit the deformation caused by the external force to the acoustic transducing unit. The acoustic transducing unit refers to a part of the laminated structure that converts the deformation of the vibration unit into an electrical signal. Specifically, the base structure can generate vibration based on an external vibration signal, the vibration unit deforms in response to the vibration of the base structure; the acoustic transducing unit generates an electrical signal based on the deformation of the vibration unit. It should be noted that the description of the vibration unit and the acoustic transducing unit here is only for the purpose of conveniently introducing the working principle of the laminated structure, and does not limit the actual composition and structure of the laminated structure. In fact, the vibration unit can not be necessary, and its function can be fully realized by the acoustic transducing unit. For example, after making certain changes to the structure of the acoustic transducing unit, the acoustic transducing unit can directly generate an electrical signal in response to the vibration of the base structure. The damping structure layer can refer to a structure with damping properties. In some embodiments, the damping structure layer can be a film-like structure or a plate-like structure. Further, at least one side of the damping structure layer can be connected to the base structure. In some embodiments, the damping structure layer can be located on the upper surface and / or the lower surface of the laminated structure or between the multiple layers of the laminated structure. For example, when the laminated structure is a cantilever beam, the damping structure layer can be located on the upper surface and / or the lower surface of the cantilever beam. For another example, when the laminated structure is a support arm and a mass element, and the mass element protrudes downward relative to the support arm, the damping structure layer can be located on the lower surface of the mass element and / or the upper surface of the support arm. In some embodiments, for macro-sized laminated structures and base structures, the damping structure layer can be directly bonded to the base structure or the laminated structure. In some embodiments, for micro-electromechanical system (MEMS) devices, the damping structure layer can be connected to the laminated structure and the base structure by using semiconductor processes, such as evaporation, spin coating, micro-assembly, etc. In some embodiments, the shape of the damping structure layer can be a regular or irregular shape such as a circle, an ellipse, a triangle, a quadrilateral, a hexagon, an octagon, etc. In some embodiments, the output effect of the electrical signal of the bone conduction microphone can be improved by selecting the material, size, thickness, etc. of the damping structure layer.

[0044] In some embodiments, the base structure and the laminated structure can be located in the shell 142 of the bone conduction microphone, the base structure is fixedly connected to the inner wall of the shell 142, and the laminated structure is carried on the base structure. For the specific structure of the laminated structure, reference can be made to other descriptions in the present application, such as Figure 1C and the description thereof.

[0045] When the shell 142 of the bone conduction microphone is vibrated by external force (for example, the vibration of the shell 142 caused by the vibration of the face when a person speaks), the shell 142 vibrates to cause the base structure to vibrate. Due to the different properties of the laminated structure and the shell structure (or the base structure), the laminated structure and the shell 142 cannot maintain consistent movement, thereby generating relative motion, and further causing the vibration unit of the laminated structure to deform. Further, when the vibration unit deforms, the piezoelectric layer of the acoustic transducing unit generates a potential difference (voltage) under the deformation stress of the vibration unit. The at least two electrode layers (for example, the first electrode layer and the second electrode layer) respectively located on the upper surface and the lower surface of the piezoelectric layer in the acoustic transducing unit can collect the potential difference to convert the external vibration signal into an electrical signal.

[0046] The damping of the damping structure layer is different under different stress (deformation) states, for example, it presents greater damping under high stress or large amplitude. Thus, by taking advantage of the characteristics of the laminated structure that the amplitude is small in the non-resonant region and the amplitude is large in the resonant region, the quality factor Q value in the resonant region can be reduced while ensuring that the sensitivity of the bone conduction microphone in the non-resonant region is not reduced by increasing the damping structure layer. The frequency response of the bone conduction microphone is relatively flat in the entire frequency range. The bone conduction microphone can be applied to earphones (for example, bone conduction earphones or air conduction earphones), glasses, virtual reality devices, helmets, etc. The bone conduction microphone can be placed near the head (for example, the face), the neck, the ear, and the top of the head of a person, etc. The bone conduction microphone can pick up the vibration signal of the bone when a person speaks and convert it into an electrical signal to achieve sound collection. It should be noted that the base structure is not limited to a structure independent of the shell 142 of the bone conduction microphone. In some embodiments, the base structure can also be part of the shell 142 of the bone conduction microphone.

[0047] Taking an air conduction microphone as an example, the air conduction microphone can include a moving coil microphone, a condenser microphone, etc. The sensing element 143 of the moving coil microphone can include a diaphragm, a coil, and a magnet. The magnet is used to generate a magnetic field. When there is air conduction sound, the diaphragm can vibrate, and the diaphragm vibration can drive the coil to move in the magnetic field, cutting the magnetic induction lines, thereby generating an electrical signal to achieve sound collection. The sensing element 143 of the condenser microphone can include a diaphragm, a back plate, and a power supply. The diaphragm and the back plate are placed in parallel and close to each other, and respectively constitute two poles of a capacitor. The power supply provides voltage for the two poles of the capacitor. When there is air conduction sound, the diaphragm can vibrate, thereby changing the distance between the two poles of the capacitor, and changing the capacitance of the capacitor. Under the condition that the voltage remains unchanged, the amount of electricity in the capacitor changes, thereby generating an electrical signal to achieve sound collection.

[0048] The processor 144 can acquire the electrical signal from the sensing element 143 and perform signal processing. In some embodiments, the signal processing can include frequency modulation processing, amplitude modulation processing, filtering processing, noise reduction processing, etc. The processor 144 can include a microcontroller, a microprocessor, an application specific integrated circuit (ASIC), an application specific instruction set processor (ASIP), a central processing unit (CPU), a physical processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an advanced reduced instruction set computer (ARM), a programmable logic device (PLD), or other types of processing circuitry or processors.

[0049] Figure 1C is an exemplary structural schematic diagram of a sensing element of a bone conduction microphone according to some embodiments of the present specification.

[0050] In the present embodiment, the sensing element 143 includes a base 181 and a cantilever beam 182. The base 181 is fixedly connected to the PCB 141 at the bottom, and one end of the cantilever beam 182 is fixed to the base 181, and the other end is suspended in the cavity of the shell 142. The cantilever beam 182 can include the aforementioned laminated structure. The laminated structure includes a vibration unit and an acoustic transduction unit. The vibration unit can include an elastic layer. The acoustic transduction unit can include a first electrode layer, a piezoelectric layer, and a second electrode layer arranged in order from top to bottom, and the elastic layer is located on the surface of the first electrode layer or the second electrode layer. The elastic layer can deform during vibration, the piezoelectric layer generates an electrical signal based on the deformation of the elastic layer, and the first electrode layer and the second electrode layer can collect the electrical signal. By way of example only, the vibration unit can include a first elastic layer and a second elastic layer arranged in order from top to bottom. The first elastic layer and the second elastic layer can be plate-shaped structures made of semiconductor materials.

[0051] In some embodiments, the cantilever beam 182 can also include other structural layers, such as a seed layer, a damping layer, etc., which are not specifically limited in the present specification. For example only, as shown in Figure 1C The cantilever beam 182 can be composed of an elastic layer 1431, an upper electrode 1432, a functional layer 1433, a bottom electrode 1434, and a seed layer 1435 in order from top to bottom. In some embodiments, the material of the seed layer 1435 can be consistent with the material of the functional layer 1433. In some embodiments, the base 181 for supporting the cantilever beam 182 can be made of semiconductor materials such as Si.

[0052] Figure 2A is a mechanical equivalent schematic diagram of an exemplary sensing device according to some embodiments of the present specification. As Figure 2AAs shown, the sensing device 200 may include the sensing structure 100 and the resonant system 210. In some embodiments, the sensing device 200 may be considered as adding the resonant system 210 to the sensing structure 100. For example, in this embodiment, the resonant system 210 may be a spring (K m4 )-Mass(M m4 )-damping(R m4 ) system. Figure 1A Taking the sensing structure 100 shown as an example, the resonant system 210 can be coupled between the housing 110 and the sensing element 120 of the sensing structure 100. Due to the action of the resonant system 210, when the housing 110 receives an external vibration signal, the external vibration signal is transmitted to the sensing element 120 through the housing region connected to the sensing element 120 and the housing region connected to the resonant system 210, respectively. As a result, the mechanical response of the sensing device 200 is different from that of the sensing structure 100. Accordingly, the electrical, acoustic, and / or thermal responses of the sensing device 200 are also different from those of the sensing structure 100.

[0053] In some embodiments, the resonant system 210 can be formed by an elastic structure (e.g., an elastic rod, an elastic sheet, an elastic vibration membrane, an elastic block, an elastic mesh bracket, a composite structure of an elastic connection structure (e.g., a lightweight spring) and a mass element (e.g., a mass block) connected to the sensing element 120 and having a certain mass. In some embodiments, the resonant system 210 may include one or more elastic rods. The two ends of the elastic rod are fixedly connected to the shell 110 and the sensing element 120, respectively. In some embodiments, the resonant system 210 may be a combination of at least one group of elastic connection structures (e.g., a lightweight spring, a lightweight elastic rod, an elastic vibration membrane, etc.) and a mass element. For example, the elastic connection structure may include an elastic vibration membrane, the two ends of the elastic vibration membrane are connected to the shell 110, and the mass block is fixedly connected to or placed on the elastic vibration membrane. More descriptions about the formation of the resonant system 210 by the combination of the elastic vibration membrane and the mass block can be found elsewhere in this specification (e.g., Figure 6 In some embodiments, the resonant system 210 may be integrally manufactured with the sensor element 120. For example, the resonant system 210 in the form of an elastic rod may be integrally manufactured with the sensor element 120 by injection molding or physical growth.

[0054] In some embodiments, the resonant system in the sensing device provided in the embodiments of this specification may be equivalent to a vibration model. Figure 3 Schematic diagram of an equivalent vibration model of a resonant system according to some embodiments of this specification. Figure 3 As shown, the resonant system (e.g., Figure 2AThe resonant system 210 shown in FIG can be simplified to be equivalent to a mass-spring-damper system. The mass-spring-damper system is subjected to forced vibration under the action of the excitation force F, and its vibration law conforms to the law of the mass-spring-damper system. For the resonant system, the elastic vibration membrane (for example, Figure 6 The elastic vibration membrane 621 shown in FIG. 6 provides a spring and a damping function for the resonant system 210. The mass block (eg, Figure 6 The mass is provided by a mass block 622) shown.

[0055] The motion of this resonant system can be described by the following differential equation:

[0056]

[0057] Where M is the mass of the resonant system, R is the damping of the resonant system, K is the elastic coefficient of the resonant system, F is the driving force amplitude, x is the displacement of the resonant system, and ω is the circular frequency of the external force. Solving the above equation for the steady-state displacement yields:

[0058] x=x a cos(ωt-θ), (2)

[0059] in,

[0060] Combine Figure 1A 、 Figure 2A and Figure 3 When the sensing device 200 is actually working, x corresponds to the deformation of the vibration-to-electrical signal conversion part of the sensing element 120 in the sensing structure 100. The magnitude of x ultimately corresponds to the magnitude of the electrical signal output. The displacement amplitude ratio (normalized) is:

[0061]

[0062] in, is the mechanical quality factor; is the static displacement amplitude (or the displacement amplitude when ω=0).

[0063] The sensor device 200 is composed of a resonant system with different parameters (elastic coefficient, mass, damping), and its normalized displacement resonance curve is as follows: Figure 4 As shown. Among them, the horizontal axis corresponds to the ratio of the frequency of the external force (or vibration) to the resonant frequency of the system The vertical axis corresponds to the A value of formula (3). It can be seen that for different sensor devices 200, their resonant systems are different and have different mechanical quality factors Q m The value corresponds to different curves in the figure, and the displacement A is different. The ratio of the frequency of the external force (or vibration) to the resonant frequency of the system At point 1, the system resonates, and the displacement changes the most. Q m The greater the value of the resonant system, the greater the value of A, and the steeper the curve; while the smaller the value of the resonant system, the smaller the value of A, and the flatter the curve, so the quality factor Q m of the resonant system can be adjusted by adjusting the quality factor Q m of the resonant system (for example, changing its structure).

[0064] The principle of the sensor structure generating a voltage signal is that the vibration-electrical signal conversion device (for example, the sensor element 120) and the sensor device shell (for example, the shell 110) generate relative displacement (for example, the electret microphone changes the distance between the diaphragm and the substrate by deforming the diaphragm to form a voltage signal; the cantilever bone conduction sensor structure deforms the cantilever vibration device to generate a reverse piezoelectric effect to form an electrical signal), and the greater the displacement, the greater the output signal. Obviously, the vibration-electrical signal conversion module of the sensor structure completely conforms to the displacement resonance curve as shown in Figure 4 .

[0065] In some embodiments, the resonant system can also include an elastic support component, and the elastic diaphragm and the elastic support component can collectively act as an equivalent spring, and the overall elastic coefficient K value is lower, which can play a role in amplifying deformation, thereby making the sensitivity of the sensor device 200 higher. In this embodiment, in a specific vibration mode, when the mass block moves up and down under the action of inertia, it will not only pull the elastic diaphragm to bend and deform, but also pull the elastic support component to deform in the longitudinal and transverse directions, thereby amplifying the displacement of the mass block.

[0066] Based on the above equation, the resonant frequency (i.e., the second resonant frequency) of the resonant system 210 is:

[0067]

[0068] where ω0 is the resonant frequency of the system.

[0069] The relationship between the resonant frequency of the sensor device and the resonant frequency of the resonant system 210 is:

[0070] f = ω0 / (2*pi) (5)

[0071] where f is the resonant frequency of the sensor device.

[0072] Combining the above formulas (4) and (5), when the When the resonance frequency is changed, the sensitivity of the signal before the resonance frequency is improved, but after the resonance frequency, there is a range of frequencies in which the sensitivity of the signal is reduced. When adjusting the sensitivity by adjusting the resonance frequency of the sensing device 200 (e.g., adjusting the second resonance frequency provided by the resonance system 210), the frequency range needs to be considered. In some embodiments, the resonance frequency of the sensing device 200 is between 1500 Hz and 6000 Hz. In some embodiments, the resonance frequency of the sensing device 200 is between 1500 Hz and 3000 Hz. In some embodiments, the resonance frequency of the sensing device 200 is between 2000 Hz and 2500 Hz.

[0073] In some embodiments, the frequency response curve of the sensing device 200 includes at least two resonance peaks. The at least two resonance peaks include a first resonance peak and a second resonance peak. The first resonance peak is a resonance peak corresponding to the sensing structure 100, and the corresponding resonance frequency is mainly related to the properties (e.g., shape, material, structure, etc.) of the sensing element 120. The second resonance peak is a resonance peak generated by the additional system (for the sensing device 200, the additional system is the resonance system 210) of the sensing structure 100, and the corresponding resonance frequency is mainly related to one or more mechanical parameters (e.g., equivalent spring (K m4 ), mass (M m4 ), damping (R m4 ), etc.) of the additional system. In order to make the sensing device 200 applicable to different scenarios, the corresponding resonance frequency of the first resonance peak (also called the first resonance frequency) and the corresponding resonance frequency of the second resonance peak (also called the second resonance frequency) can satisfy different relationships. For example, the second resonance frequency can be less than, equal to, or greater than the first resonance frequency. In some embodiments, in order to improve the sensitivity of the sensing device 200 at a lower frequency band, the second resonance frequency can be less than the first resonance frequency. For example, the difference between the first resonance frequency and the second resonance frequency can be in the range of 200 Hz-15000 Hz. For another example, the difference between the first resonance frequency and the second resonance frequency can be in the range of 500 Hz-8000 Hz. For another example, the difference between the first resonance frequency and the second resonance frequency can be in the range of 1000 Hz-5000 Hz.

[0074] For the purpose of illustration only, due to the existence of the second resonance peak corresponding to the resonance system 210, the frequency response curve of the sensing device 200, especially in the mid-low frequency band where the voice information is relatively rich, will be improved, so that the sensitivity of the sensing device 200 will be improved compared with the sensing structure 100. In addition, due to the action of the resonance system 210 on the sensing element 120, the vibration characteristics of the sensing structure 100 will change compared with the case without the resonance system 210. Specifically, the resonance system 210 acts on the sensing element 120, which can affect the mass, stiffness and / or damping of the sensing structure 100, and the effect is equivalent to changing (for example, reducing) the Q value of the first resonance peak of the sensing device 200 relative to the Q value of the sensing structure 100 without the first resonance system 210. The more specific introduction of the frequency response curve of the sensing device 200 and the first resonance peak and the second resonance peak will be given below in combination with the following figures. Figure 5A and Figure 5B The frequency response curve of the sensing device 200 and the first resonance peak and the second resonance peak will be introduced more specifically.

[0075] Figure 5A is an example of the frequency response curve of the sensing device 200 according to some embodiments of the present specification. As shown in Figure 5A , the dashed line represents the frequency response curve 510 of the sensing structure 100, and the solid line represents the frequency response curve 520 of the sensing device 200. The abscissa represents the frequency in hertz (Hz), and the ordinate represents the sensitivity in decibels (dBV). The frequency response curve 510 includes a resonance peak 511 corresponding to the resonance frequency of the sensing structure 100. The frequency response curve 520 includes a first resonance peak 521 and a second resonance peak 522. For the sensing device 200, the first resonance peak 521 corresponds to the first resonance frequency, and the second resonance peak 522 is formed by the action of the resonance system 210, and the corresponding frequency is the second resonance frequency.

[0076] It should be noted that the second resonance peak 522 shown in the figure is to the left of the first resonance peak 521, meaning that the frequency corresponding to the second resonance peak 522 is lower than the frequency corresponding to the first resonance peak. In some embodiments, the mechanical parameters of the sensing structure 100 or the resonant system 210 can be modified to make the frequency corresponding to the second resonance peak 522 (i.e., the first resonance frequency) higher than the frequency corresponding to the first resonance peak 521 (i.e., the second resonance peak 522 is to the right of the first resonance peak 521. In some embodiments, when the resonant system 210 includes a vibration pickup unit composed of an elastic diaphragm and a mass, the second resonance peak 522 can be to the left of the first resonance peak 521, meaning that the second resonance frequency is lower than the first resonance frequency. For example, in some embodiments, the difference between the second resonance frequency and the first resonance frequency is between 200 Hz and 15,000 Hz. For another example, in some embodiments, the difference between the second resonance frequency and the first resonance frequency is between 1,000 Hz and 8,000 Hz. For another example, in some embodiments, the difference between the second resonance frequency and the first resonance frequency is between 2,000 Hz and 6,000 Hz. In some embodiments, the position of the second resonance peak 522 is related to the elastic vibration membrane (eg, Figure 6 The elastic vibration membrane 621 shown) and / or the mass block (eg, Figure 6 The second resonance frequency is related to the mechanical parameters of the mass block 622 shown in FIG. For example, the greater the mass of the mass block, the smaller the second resonance frequency, and the second resonance peak 522 will shift to a low frequency, or the better the elasticity of the elastic vibration membrane, the larger the second resonance frequency, and the second resonance peak 522 will shift to a high frequency. In some embodiments, for the sensing device 200 with an internal liquid filled as a resonant system, its second resonance peak 522 is to the left of the first resonance peak 521, and its position can be related to the properties of the filled liquid (for example, density, kinematic viscosity, volume, etc.) and the properties of the elastic vibration membrane. As the density of the liquid decreases or the kinematic viscosity increases, its resonance peak will shift to a high frequency.

[0077] In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 100 Hz to 18,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 100 Hz to 10,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 500 Hz to 10,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 1,000 Hz to 7,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 1,500 Hz to 5,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 2,000 Hz to 5,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 2,000 Hz to 4,000 Hz. In some embodiments, the frequency corresponding to the resonance peak 511 is in the range of 3,000 Hz to 4,000 Hz.

[0078] In some embodiments, the frequency corresponding to the first resonance peak 521 (i.e. the first resonance frequency) can be the same as the resonance frequency corresponding to the resonance peak 511. For example, when the resonance system includes a pick-up unit formed by a combination of an elastic diaphragm and a mass, the resonance system has little effect on the stiffness, mass and damping of the sensing structure 100 itself, so the first resonance frequency of the sensing structure 100 in the sensing device 200 does not change relative to the resonance frequency of the sensing structure 100 itself (i.e. the resonance frequency corresponding to the resonance peak 511).

[0079] In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 100 Hz to 18000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 500 Hz to 10000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 1000 Hz to 10000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 1500 Hz to 7000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 1500 Hz to 5000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 2000 Hz to 5000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 2000 Hz to 4000 Hz. In some embodiments, the frequency corresponding to the first resonance peak 521 is in the range of 3000 Hz to 4000 Hz.

[0080] In some embodiments, the resonance frequency corresponding to the first resonance peak 521 (i.e. the first resonance frequency) is different from the resonance frequency corresponding to the resonance peak 511. For example, for the sensing device 200 shown in FIG. 1, the liquid in the cavity of the shell 110 is filled with liquid as the resonance system 210, and because the liquid is incompressible, the stiffness of the system itself becomes larger, so the first frequency corresponding to the first resonance peak 521 becomes larger than the resonance frequency corresponding to the resonance peak 511, i.e. the first resonance peak 521 is shifted to the right relative to the resonance peak 511. Figure 2B In some embodiments, the resonance frequency corresponding to the first resonance peak 521 (i.e. the first resonance frequency) is different from the resonance frequency corresponding to the resonance peak 511. For example, for the sensing device 200 shown in FIG. 1, the liquid in the cavity of the shell 110 is filled with liquid as the resonance system 210, and because the liquid is incompressible, the stiffness of the system itself becomes larger, so the first frequency corresponding to the first resonance peak 521 becomes larger than the resonance frequency corresponding to the resonance peak 511, i.e. the first resonance peak 521 is shifted to the right relative to the resonance peak 511.

[0081] In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 50 Hz to 15,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 50 Hz to 10,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 50 Hz to 6,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 100 Hz to 5,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 500 Hz to 5,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 1,000 Hz to 5,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 1,000 Hz to 2,000 Hz. In some embodiments, the second resonance peak 522 corresponds to a frequency in the range of 1,500 Hz to 2,000 Hz. In some embodiments, the two resonance peaks 521 and 522 on the frequency response curve 520 can be adjusted by tuning one or more mechanical parameters in the resonant system (e.g., the mass of the mass block 622, the stiffness of the elastic diaphragm 621, the dimensions of the first acoustic cavity 630, etc.) to make the valley between the two resonance peaks 521 and 522 flatter, thereby improving the output quality of the sensing device 200. Figure 6 In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 50 dBV. In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 20 dBV. In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 15 dBV. In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 10 dBV. In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 8 dBV. In some embodiments, the difference in sensitivity between the valley between the first resonance peak 521 corresponding to the first resonance frequency and the second resonance peak 522 corresponding to the second resonance frequency and the peak value of the higher resonance peak of the two is no more than 5 dBV.

[0082] Correspondingly, the difference between the resonant frequencies corresponding to the first resonant peak 521 and the second resonant peak 522 (the first resonant frequency corresponding to the first resonant peak 521 is denoted as f0(approximately the same as the resonant peak 511), the second resonant frequency corresponding to the second resonant peak 522 is denoted as f1, and the difference between the resonant frequencies corresponding to the first resonant peak 521 and the second resonant peak 522, i.e., the difference between the first resonant frequency f0and the second resonant frequency f1, is denoted as a frequency difference Af1) is within a certain range, which can make the frequency response curve between the resonant peaks 521 and 522 relatively flat. In some embodiments, the frequency difference Af1is within a range of 200 Hz to 15000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.03 to 8. In some embodiments, the frequency difference Af1is within a range of 200 Hz to 12000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.3 to 6. In some embodiments, the frequency difference Af1is within a range of 200 Hz to 8000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.3 to 3. In some embodiments, the frequency difference Af1is within a range of 200 Hz to 3000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.2 to 0.7. In some embodiments, the frequency difference Af1is within a range of 200 Hz to 2000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.2 to 0.65. In some embodiments, the frequency difference Af1is within a range of 500 Hz to 2000 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.25 to 0.65. In some embodiments, the frequency difference Af1is within a range of 500 Hz to 1500 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.25 to 0.6. In some embodiments, the frequency difference Af1is within a range of 800 Hz to 1500 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.3 to 0.6. In some embodiments, the frequency difference Af1is within a range of 1000 Hz to 1500 Hz, and the ratio of the frequency difference Af1to f0is within a range of 0.35 to 0.6.

[0083] Continuing to refer to Figure 5AAs shown, compared with the frequency response curve 510, the frequency response curve 520 has a higher and more stable sensitivity improvement (i.e. difference, denoted as AV1) within the frequency range of the resonance frequency fl corresponding to the second resonance peak 522. In some embodiments, the improvement AV1 is within the range of 10 dBV~60 dBV. In some embodiments, the improvement AV1 is within the range of 10 dBV~50 dBV. In some embodiments, the improvement AV1 is within the range of 15 dBV~50 dBV. In some embodiments, the improvement AV1 is within the range of 15 dBV~40 dBV. In some embodiments, the improvement AV1 is within the range of 20 dBV~40 dBV. In some embodiments, the improvement AV1 is within the range of 25 dBV~40 dBV. In some embodiments, the improvement AV1 is within the range of 30 dBV~40 dBV.

[0084] In some embodiments, the presence of the resonant system 210 can cause a suppression effect on the resonance peak corresponding to the sensing structure 100 in the sensing device 200, so that the Q value at the first resonance peak 521 of the frequency response curve 520 is relatively low, the frequency response curve is more flattened within the required frequency band (e.g. low and medium frequency), and the difference between the peak value of the highest peak and the valley value of the lowest valley (also known as the peak-to-valley value, denoted as AV2) of the overall frequency response curve 520 is within a certain range. In some embodiments, the peak-to-valley value does not exceed 30 dBV. In some embodiments, the peak-to-valley value does not exceed 20 dBV. In some embodiments, the peak-to-valley value does not exceed 10 dBV. In some embodiments, the peak-to-valley value does not exceed 8 dBV. In some embodiments, the peak-to-valley value does not exceed 5 dBV.

[0085] In some embodiments, the frequency response of the sensing device 200 can be described by one or more of the relevant parameters of the curve 520, such as the peak value, frequency of the first resonance peak 521, the peak value, frequency, Q value of the second resonance peak 522, AV1, AV2, the ratio of AV1 to f0, the ratio of the peak-to-valley value to the peak value of the highest peak, the first-order coefficient, the second-order coefficient, the third-order coefficient of the equation determined by fitting the frequency response curve, etc. In some embodiments, when the resonant system 210 includes the resonant unit 211, the frequency response of the sensing device 200 can be related to the mechanical parameters of the mass and the elastic diaphragm (e.g. mass, damping, stiffness, etc.). In some embodiments, when the resonant system 210 is formed by a liquid, for example Figure 2BThe frequency response of the sensing device 200 shown can be related to the properties of the liquid filled therein and / or the parameters of the sensing structure 100. The properties of the liquid may include, for example, the liquid density, the liquid kinematic viscosity, the liquid volume, the presence of bubbles, the bubble volume, the bubble location, the number of bubbles, etc. The parameters of the sensing structure 100 may include, for example, the internal structure, size, and stiffness of the housing 110, the mass of the sensing structure 100, and / or the size and stiffness of the sensing element 120 (e.g., a cantilever beam).

[0086] Figure 5B is an exemplary frequency response curve of another sensing device provided according to some embodiments of this specification. Figure 5B As shown, the frequency response curve 560 represented by the dashed line is the frequency response curve of the sensing structure 100, and the frequency response curve 570 represented by the solid line is the frequency response curve of the sensing device 200. The frequency response curve 560 includes a resonance peak 561, which corresponds to the resonant frequency of the sensing structure 100. In some embodiments, the higher resonant frequency corresponding to the sensing structure 100 is not in the desired frequency range (e.g., 100-5000 Hz, 500-7000 Hz, etc.). In some embodiments, the resonant frequency corresponding to the sensing structure 100 can be in a higher frequency range. For example, in some embodiments, the resonant frequency corresponding to the sensing structure 100 is higher than 7000 Hz. In some embodiments, the resonant frequency corresponding to the sensing structure 100 is higher than 10000 Hz. In some embodiments, the resonant frequency corresponding to the sensing structure 100 is higher than 12000 Hz. In some embodiments, the resonant frequency corresponding to the sensing structure 100 is higher than 15000 Hz. Accordingly, since the sensing device 200 has an additional resonance system, the sensing device 200 can have higher rigidity, so that the sensing device 200 has higher impact resistance and reliability.

[0087] The frequency response curve 570 includes a first resonance peak (not shown) and a second resonance peak 572. In some embodiments, the frequency corresponding to the first resonance peak is close to or the same as the resonance frequency corresponding to the sensing structure 100 in the frequency response curve 560. In some embodiments, the frequency response curve 570 is similar to the first resonance peak. Figure 5A The frequency response curve 520 in FIG is substantially the same except that the first resonance peak is shifted to the right. The frequency corresponding to the second resonance peak 572 is Figure 5A The frequency range corresponding to the second resonance peak 522 is the same or similar.

[0088] In some embodiments, the difference between the maximum and minimum sensitivity in the frequency response curve 570 in a desired frequency range (e.g., within 2000 Hz, within 3000 Hz, within 5000 Hz, etc.) should be kept within a certain range to ensure stability of the sensing device 200. In some embodiments, the difference between the minimum sensitivity in a frequency range within the second resonant frequency and the sensitivity at the peak of the second resonant peak 572 corresponding to the second resonant frequency is no more than 40 dBV in a desired frequency range (e.g., the second resonant frequency range). In some embodiments, the difference between the minimum sensitivity in a frequency range within the second resonant frequency and the sensitivity at the peak of the second resonant peak 572 corresponding to the second resonant frequency is no more than 30 dBV in a desired frequency range (e.g., the second resonant frequency range). In some embodiments, the difference between the minimum sensitivity in a frequency range within the second resonant frequency and the sensitivity at the peak of the second resonant peak 572 corresponding to the second resonant frequency is no more than 20 dBV in a desired frequency range (e.g., the second resonant frequency range). In some embodiments, the difference between the minimum sensitivity in a frequency range within the second resonant frequency and the sensitivity at the peak of the second resonant peak 572 corresponding to the second resonant frequency is no more than 10 dBV in a desired frequency range (e.g., the second resonant frequency range).

[0089] In some embodiments, the difference between the resonant frequencies corresponding to the first and second resonant peaks (the frequency of the first resonant peak is denoted as f0(approximately corresponding to the resonant peak 561), the frequency of the second resonant peak 572 is denoted as f1, and the difference between the two resonant frequencies is denoted as the frequency difference Af2) is within a certain range. In some embodiments, the frequency difference Af2is within the range of 200-15000 Hz, and the ratio of the frequency difference Af2to f0is within the range of 0.03-8. In some embodiments, the frequency difference Af1is within the range of 200 Hz-12000 Hz, and the ratio of the frequency difference Af1to f0is within the range of 0.3-6. In some embodiments, the frequency difference Af1is within the range of 200 Hz-8000 Hz, and the ratio of the frequency difference Af1to f0is within the range of 0.3-3. In some embodiments, the frequency difference Af2is within the range of 1000-6000 Hz, and the ratio of the frequency difference Af2to f0is within the range of 0.2-0.65. In some embodiments, the frequency difference Af2is within the range of 2000-6000 Hz, and the ratio of the frequency difference Af2to f0is within the range of 0.3-0.65. In some embodiments, the frequency difference Af2is within the range of 3000-5000 Hz, and the ratio of the frequency difference Af2to f0is within the range of 0.3-0.5. In some embodiments, the frequency difference Af2is within the range of 3000-4000 Hz, and the ratio of the frequency difference Af2to f0is within the range of 0.3-0.4.

[0090] Further, compared with the frequency response curve 560, the frequency response curve 570 has a higher and more stable sensitivity improvement (i.e. difference, denoted as AV3) within the frequency range within the second resonance peak 572 corresponding resonance frequency fl. In some embodiments, the improvement AV3 is within the range of 10 dBV~60 dBV. In some embodiments, the improvement AV3 is within the range of 10 dBV~50 dBV. In some embodiments, the improvement AV3 is within the range of 15 dBV~50 dBV. In some embodiments, the improvement AV3 is within the range of 15 dBV~40 dBV. In some embodiments, the improvement AV3 is within the range of 20 dBV~40 dBV. In some embodiments, the improvement AV3 is within the range of 25 dBV~40 dBV. In some embodiments, the improvement AV3 is within the range of 30 dBV~40 dBV.

[0091] In some embodiments, the frequency response of the sensing device 200 can be described by one or more of the relevant parameters of the curve 570, such as the peak value, frequency of the primary resonance peak, the peak value, frequency, Q value of the second resonance peak 572, AV3, the ratio of AV3 to f0, the ratio of the maximum sensitivity to the minimum sensitivity within the desired frequency range, the first order coefficient, the second order coefficient, the third order coefficient of the equation determined by fitting the frequency response curve, etc. In some embodiments, the frequency response of the sensing device 200 can be related to the properties of the filled liquid and / or the parameters of the sensing structure 100. In some embodiments, to obtain the desired output frequency response (e.g. the frequency response curve 570) of the sensing device 200, the ranges of the above-mentioned parameters (also referred to as frequency response influencing factors, including the parameters of the pick-up unit 211 and / or the sensing structure 100) that affect the frequency response can be determined by computer simulation, modal experiment, etc. in the same or similar manner as described in the method described in the Figure 5A above, which will not be repeated here.

[0092] In some embodiments, when the resonant system 210 is formed by a liquid, such as when the liquid is filled between a plurality of elastic diaphragms as the resonant system 210 (as shown in Figure 2B In some embodiments, the frequency response of the sensing device 200 can be related to the properties of the filled liquid and / or the parameters of the sensing structure 100 and the elastic diaphragms. In some embodiments, the properties of the liquid can include, but are not limited to, one or more of the liquid density, the liquid kinematic viscosity, the liquid volume, whether there are air bubbles, the air bubble volume, the air bubble position, the air bubble number, etc. In some embodiments, the parameters of the sensing structure 100 can include, but are not limited to, the internal structure, size, stiffness of the housing 110, the mass of the sensing structure 100, and / or the size, stiffness, etc. of the sensing element 120 (e.g. the suspension membrane). In some embodiments, the parameters of the elastic diaphragm can include, but are not limited to, the size, Young's modulus, stiffness, damping, elongation, hardness, etc.

[0093] In some embodiments, to obtain a desired frequency response of the sensing device 200 (e.g., the frequency response curve 520), the parameter ranges of the above-listed factors affecting the frequency response (also referred to as frequency response affecting factors, including the resonant system (e.g., the pick-up unit 620) and / or the sensing structure 100) can be determined through computer simulation, modal experiment, etc. In some embodiments, the effects of each factor on the sensing device 200 can be determined one by one based on simulation, by controlling variables. For example, the performance of the sensing device corresponding to different masses of the mass block can be tested while the elastic diaphragm remains unchanged. For another example, the performance of the sensing device with different cavity structure features can be tested while the same liquid is filled in the cavities. Figure 6

[0094] In some embodiments, some factors are correlated with other factors in terms of their effects on the frequency response of the sensing device 200, and thus the effects of the parameter pairs or parameter groups on the frequency response of the sensing device 200 can be determined. For example, for the resonant system shown in the figure, when the shape of the mass block 622 is changed, the mass of the mass block 622 changes, the volume changes, and the contact area with the elastic diaphragm 621 also changes. Thus, the shape, mass, volume, and contact area of the mass block with the elastic diaphragm 621 (or any two parameter ratios, or the product of at least two parameters, etc.) can be used as a parameter group, and the performance of the sensing device with different parameter pairs or parameter group features can be tested. Figure 6

[0095] For example, for the sensing device 200 including mass blocks with different masses, the greater the mass of the mass block, the smaller the Q value of the frequency response of the sensing device 200.

[0096] It should be noted that the above description of the frequency response curve of the sensing device 200 is only an exemplary description, and does not limit the present specification to the scope of the embodiments. It can be understood that, for those skilled in the art, after understanding the principles of the system, the structure and composition of the system can be adjusted arbitrarily without departing from the principles. Such variations are within the scope of protection of the present specification.

[0097] ​​In some embodiments, the resonant system 210 can reduce the external impact on the sensing element to protect the sensing element. For example, the resonant system 210 includes an elastic structure (e.g., an elastic diaphragm), and the elasticity of the elastic structure can absorb the external impact load and reduce the possibility of damage to the sensing device due to the external impact. For another example, the resonant system 210 can also include a mass block, in which the mass of the polymer material is more than 80%. The elastic properties of the polymer material mass block can also absorb the external impact load, thereby effectively reducing the stress concentration at the connection between the elastic diaphragm and the shell 110 of the sensing structure 100, and reducing the possibility of damage to the sensing device due to the external impact. For yet another example, if the resonant system 210 is a liquid filled in the cavity of the sensing structure 100, due to the viscous effect of the liquid and the small stiffness of the liquid relative to the device material, the impact reliability when the sensing device 200 receives the external impact load (e.g., a bone conduction microphone requires an impact resistance of 10,000g acceleration without damage). Specifically, due to the viscous effect of the liquid, part of the impact energy can be absorbed and consumed, so that the impact load on the sensing element 120 is greatly reduced.

[0098] It should be noted that the sensing device 200 in the above embodiments can be regarded as adding the resonant system 210 to the sensing structure 100, and the resonant system 210 is coupled between the shell 110 of the sensing structure 100 and the sensing element 120, and the shell 110 of the sensing structure 100 can be regarded as the shell of the sensing device 200. In some other embodiments, the shell for accommodating the resonant system 210 can also be a shell structure independent of the shell 110 of the sensing structure 100, and the shell structure is connected to the shell 110 of the sensing structure 100, and the cavities of the two are connected.

[0099] In the following, the sensing device 600 will be described in detail taking the resonant system formed by the elastic structure (e.g., the structure combined by the elastic diaphragm and the mass block) as an example.

[0100] Figure 6 is a structural schematic diagram of a sensing device provided according to some embodiments of the present specification. As shown in Figure 6As shown, the sensing device 600 can include a sensing structure 610 and a resonance system. In some embodiments, the sensing structure 610 can include a housing 611, a printed circuit board (PCB) 612, a processor 613, and a sensing element 614. The housing 611 can be a regular or irregular solid structure with a cavity (i.e., a hollow portion) inside, for example, can be a hollow frame structure, including but not limited to a rectangular frame, a circular frame, a regular polygonal frame, and any irregular shape. In some embodiments, the sensing element 614 and the processor 613 are respectively connected to the upper surface of the PCB 612, the PCB 612 is located in the cavity inside the housing 611, the housing 611 seals the sensing element 614, the processor 613, the PCB 612 and the circuit and other components arranged thereon, and the PCB 612 divides the cavity inside the housing 611 into two chambers arranged in an upper and lower manner. For specific content of the housing 611, the PCB 612, the processor 613, and the sensing element 614, please refer to the description of the sensing device 100 in the foregoing embodiment Figure 1B The specific content of the PCB 141, the housing 142, the sensing element 143, and the processor 144 is not repeated here.

[0101] The resonance system is located in the chamber corresponding to the lower surface of the PCB 612. In some embodiments, the resonance system can include a vibration pickup unit 620, which can generate vibration in response to the vibration of the housing 611, so that the sensing device 600 forms a second resonance frequency smaller than the corresponding first resonance frequency of the sensing structure in a specific frequency band (for example, a human voice frequency band), thereby improving the sensitivity of the sensing device 600 in the specific frequency band. In some embodiments, the vibration pickup unit 620 can include an elastic vibration membrane 621 and a mass block 622. The elastic vibration membrane 621 can be connected to the housing 611 through its peripheral side, for example, the elastic vibration membrane 621 can be connected to the inner wall of the housing 611 by gluing, clamping or the like. The mass block 622 is arranged on the elastic vibration membrane 621. Specifically, the mass block 622 can be arranged on the upper surface or the lower surface of the elastic vibration membrane 621. The upper surface of the elastic vibration membrane 621 can refer to the side of the elastic vibration membrane 621 facing the PCB 612, and the lower surface of the elastic vibration membrane 621 can refer to the side of the elastic vibration membrane 621 away from the PCB 612. In some embodiments, the number of mass blocks 622 can be multiple, and multiple mass blocks 622 can be simultaneously located on the upper surface or the lower surface of the elastic vibration membrane 621. In some embodiments, part of the multiple mass blocks 622 can be arranged on the upper surface of the elastic vibration membrane 621, and the other part of the mass blocks 622 can be located on the lower surface of the elastic vibration membrane 621. In some embodiments, the mass block 622 can also be embedded in the elastic vibration membrane 621.

[0102] In some embodiments, a first acoustic cavity 630 can be formed between the elastic diaphragm 621 and the sensing structure 610. Specifically, the upper surface of the elastic diaphragm 621, the PCB 612 and the housing 611 can form the first acoustic cavity 630, and the lower surface of the elastic diaphragm 621 and the housing 611 can form a second acoustic cavity 640. When the housing of the sensing device 600 (e.g., the housing 611 of the sensing structure 610) vibrates in response to an external sound signal, due to the difference in the characteristics of the vibration pickup unit 620 (the elastic diaphragm 621 and the mass block 622) and the housing 611, the elastic diaphragm 621 and the mass block 622 of the vibration pickup unit 620 will move relative to the housing 611, and the elastic diaphragm 621 and the mass block 622 will cause the sound pressure in the first acoustic cavity 630 to change during the vibration relative to the housing 611, and the sensing structure 610 can convert the external sound signal into an electrical signal based on the change in the sound pressure in the first acoustic cavity 630. Specifically, the vibration of the elastic diaphragm 621 and the mass block 622 will cause the air in the first acoustic cavity 630 to vibrate, and the air vibration can act on the sensing element 614 through one or more sound inlet holes 6121 provided on the PCB 612, and the sensing element 614 can convert the air vibration into an electrical signal or generate an electrical signal based on the change in the sound pressure in the first acoustic cavity 630, and then the processor 613 can perform signal processing on the electrical signal. In the embodiments of the present specification, by introducing a resonant system on the basis of the sensing structure 610, the second resonant frequency provided by the resonant system can enable the sensing device 600 to generate a new resonant peak (e.g., a second resonant peak) in a frequency band different from the first resonant frequency of the sensing structure 610 (e.g., near the second resonant frequency), thereby enabling the sensing device 600 to have higher sensitivity in a wider frequency band range compared to the sensing structure. In some embodiments, the second resonant frequency can be adjusted by adjusting the mechanical parameters (e.g., stiffness, mass, damping, etc.) of the resonant system, so that the sensitivity of the sensing device 600 can be adjusted. It should be noted that the comparison of the sensitivity of the sensing device with the sensitivity of the sensing structure 610 in the embodiments of the present specification can be understood as the comparison of the sensitivity of the sensing structure 610 before and after the introduction of the resonant system.

[0103] In the present embodiment, the elastic diaphragm 621 can provide stiffness and damping for the resonant system, and the mass block 622 can provide mass and damping for the resonant system. The combination of the elastic diaphragm 621 and the mass block 622 can be equivalent to a spring-mass-damping system (e.g., a spring (K Figure 2A m4 ) - mass (M m4 ) - damping (R m4 ) system shown in Figure 3 ​The elastic vibration membrane 621 and the mass 622 form a resonant system (e.g., a mass-spring-damper system as shown in FIG. 6B) and thus constitute a resonant system. Therefore, the stiffness, mass, and damping of the resonant system can be adjusted by adjusting the structure, material, etc. of the elastic vibration membrane 621 and / or the mass 622, so that the second resonant frequency provided by the resonant system can be adjusted, and thus a new resonant peak of the sensing device in a desired frequency band (e.g., near the second resonant frequency) can be generated, and the sensitivity can be improved. Therefore, the sensing device 600 can also have a higher sensitivity for the part of the external signal whose frequency is not near the first resonant frequency of the sensing structure 610.

[0104] Further, the sensitivity of the sensing device 600 can be related to the stiffness of the elastic vibration membrane 621, the mass of the mass 622, and the spatial volume of the cavity (i.e., the first acoustic cavity 630) between the elastic vibration membrane 621 and the sensing structure 610. In some embodiments, the smaller the stiffness of the elastic vibration membrane 621, the larger the mass of the mass 622, or the smaller the spatial volume of the first acoustic cavity 630, the higher the sensitivity of the sensing device.

[0105] In some embodiments, the mechanical parameters (e.g., material, size, shape, etc.) of the mass 622 can be adjusted to make the sensing device 600 have a more ideal frequency response, so that the resonant frequency, sensitivity, and reliability of the sensing device 600 can be adjusted. In some embodiments, the mass 622 can be a regular or irregular shape such as a cuboid, a cylinder, a sphere, an ellipsoid, etc.

[0106] In some embodiments, the mass 622 can be made of a high polymer material such as polyurethane (PU), polyamide (PA) (commonly known as nylon), polytetrafluoroethylene (PTFE), phenol-formaldehyde (PF), etc. The elastic properties of the high polymer material mass 622 can absorb external impact loads, thereby effectively reducing the stress concentration at the connection between the elastic vibration membrane and the shell of the sensing structure, and further reducing the possibility of damage to the sensing device due to external impact. In order to improve the stability of the sensing device, in some embodiments, the mass of the high polymer material in the mass 622 can be more than 40%. In some embodiments, the mass of the high polymer material in the mass 622 can be more than 60%. In some embodiments, the mass of the high polymer material in the mass 622 can be more than 80%. In some embodiments, the mass of the high polymer material in the mass 622 can be more than 90%. In some embodiments, the mass 622 is made of a high polymer material.

[0107] In some embodiments, the rigidity of the elastic diaphragm 621 can be adjusted by adjusting the mechanical parameters (e.g., Young's modulus, tensile strength, elongation, and hardness shore A) of the elastic diaphragm 621, so that the sensing device 600 obtains a more ideal frequency response, thereby being able to adjust the resonant frequency and sensitivity of the sensing device 600. In some embodiments, in order to make the sensitivity of the sensing device 600 have a better improvement relative to the sensing structure 610, the second resonant frequency provided by the resonant system can be lower than the first resonant frequency of the sensing structure 610. For example, the second resonant frequency is 1000 Hz-10000 Hz lower than the first resonant frequency, which can make the sensitivity of the sensing device 600 improve by 3 dB-30 dB compared with the sensing structure 610.

[0108] In some embodiments, the elastic diaphragm 621 can be made of a flexible high polymer material, wherein the flexible high polymer material can include but is not limited to polyimide (PI), parylene, polydimethylsiloxane (Pdms), hydrogel, etc. In some embodiments, the elastic diaphragm 621 can also be made of an inorganic rigid material, wherein the inorganic rigid material can include but is not limited to semiconductor materials such as silicon (Si) and silicon dioxide (SiO2), or metal materials such as copper, aluminum, steel, and gold. In some embodiments, the elastic diaphragm 621 can be made of a high polymer material and other materials (e.g., inorganic rigid materials). In some embodiments, the mass of the high polymer material in the elastic diaphragm 621 can exceed 40%. In some embodiments, the mass of the high polymer material in the elastic diaphragm 621 can exceed 60%. In some embodiments, the mass of the high polymer material in the elastic diaphragm 621 can exceed 80%.

[0109] In some embodiments, the sensitivity of the sensing device 600 in a specific frequency range (e.g., a human voice frequency range) can be improved by adjusting the Young’s modulus parameter of the elastic diaphragm 621. In some embodiments, the greater the Young’s modulus of the elastic diaphragm 621, the greater the stiffness, and the higher the sensitivity of the sensing device 600. In some embodiments, the Young’s modulus of the elastic diaphragm 621 can be 1 MPa to 10 GPa. In some embodiments, the Young’s modulus of the elastic diaphragm 621 can be 100 MPa to 8 GPa. In some embodiments, the Young’s modulus of the elastic diaphragm 621 can be 1 GPa to 8 GPa. In some embodiments, the Young’s modulus of the elastic diaphragm 621 can be 2 GPa to 5 GPa. It should be noted that the specific frequency range mentioned above can refer to a frequency range less than 10000 Hz. For example, the specific frequency range can be 20 Hz-9000 Hz. For another example, the specific frequency range can be 500 Hz-6000 Hz. For yet another example, the specific frequency range can be 500 Hz-2000 Hz. The specific frequency range can be adjusted according to different application scenarios of the sensing device 600. For example, when the sensing device 600 is applied to pick up the acoustic signal when the user speaks, the specific frequency range can be a human voice frequency range. For another example, when the sensing device 600 is applied to the sound signal of the external environment, the specific frequency range can be 20 Hz-10000 Hz.

[0110] In some embodiments, the sensitivity of the sensing device 600 in a specific frequency range (e.g., a human voice frequency range) can be improved by adjusting the tensile strength of the elastic diaphragm 621. The tensile strength of the elastic diaphragm 621 can be the maximum tensile stress that the elastic diaphragm 621 can withstand when necking phenomenon (i.e., concentrated deformation) occurs. In some embodiments, the greater the tensile strength of the elastic diaphragm 621, the higher the sensitivity of the sensing device 600 in a specific frequency range (e.g., a human voice frequency range). In addition, the greater the tensile strength of the elastic diaphragm 621, the better the stability of the resonant system and the entire sensing device. In some embodiments, the tensile strength of the elastic diaphragm 621 can be 0.5 MPa to 100 MPa. In some embodiments, the tensile strength of the elastic diaphragm 621 can be 5 MPa to 90 MPa. In some embodiments, the tensile strength of the elastic diaphragm 621 can be 10 MPa to 80 MPa. In some embodiments, the tensile strength of the elastic diaphragm 621 can be 20 MPa to 70 MPa. The tensile strength of the elastic diaphragm 621 can be 30 MPa to 60 MPa.

[0111] In some embodiments, the sensitivity of the sensing device in a specific frequency range (e.g., a human voice frequency range) can be improved by adjusting the elongation of the elastic diaphragm 621. The elongation of the elastic diaphragm 621 refers to the ratio of the maximum elongation length to the original elongation length of the elastic diaphragm 621 during the stretching process. In some embodiments, the greater the elongation of the elastic diaphragm 621, the higher the sensitivity of the sensing device 600 in a specific frequency range (e.g., a human voice frequency range), and the better the stability. In some embodiments, the elongation of the elastic diaphragm 621 can be 10% to 600%. In some embodiments, the elongation of the elastic diaphragm 621 can be 20% to 500%. In some embodiments, the elongation of the elastic diaphragm 621 can be 50% to 400%. In some embodiments, the elongation of the elastic diaphragm 621 can be 80% to 200%.

[0112] In some embodiments, the sensitivity of the sensing device in a specific frequency range (e.g., a human voice frequency range) can be improved by adjusting the hardness of the elastic diaphragm 621. The hardness of the elastic diaphragm 621 can refer to the Shore A hardness of the elastic diaphragm 621. In some embodiments, the smaller the hardness of the elastic diaphragm 621, the higher the sensitivity of the sensing device. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 200. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 150. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 100. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 60. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 30. In some embodiments, the Shore A hardness of the elastic diaphragm 621 is less than 10.

[0113] In some embodiments, the material of the mass 622 and the material of the elastic diaphragm 621 can be the same. For example, the mass 622 and the elastic diaphragm 621 can be made of the same high polymer material. In some embodiments, when the mass 622 and the elastic diaphragm 621 are made of the same material, the mass 622 and the elastic diaphragm 621 can be manufactured in an integrated manner (e.g., 3D printing, injection molding). When the mass 622 and the elastic diaphragm 621 are made of the same high polymer material, the mechanical parameters (e.g., Young's modulus, stiffness, etc.) of the mass 622 made of the high polymer material and the mechanical parameters of the elastic diaphragm 621 made of the high polymer material are the same or similar, and the frequency response of the mass 622 and the elastic diaphragm 621 to the vibration signal is similar, which can further reduce the stress concentration problem at the connection between the elastic diaphragm and the shell during the vibration process.

[0114] In some embodiments, the material of the mass 622 and the material of the elastic diaphragm 621 can be different. For example, the mass 622 and the elastic diaphragm 621 can be made of different kinds of polymer materials or metals, respectively, or one of the mass 622 and the elastic diaphragm 621 is made of a polymer material and the other is made of a metal. In some embodiments, when the mass 622 and the elastic diaphragm 621 are made of different materials, the mass 622 can be connected to the elastic diaphragm 621 by means of gluing, clamping, welding, or the like.

[0115] In some embodiments, the thickness of the mass 622 can be within a certain range. In some embodiments, the thickness of the mass 622 is 1 μm to 5000 μm. In some embodiments, the thickness of the mass 622 is 1 μm to 3000 μm. In some embodiments, the thickness of the mass 622 is 1 μm to 1000 μm. In some embodiments, the thickness of the mass 622 is 1 μm to 500 μm. In some embodiments, the thickness of the mass 622 is 1 μm to 200 μm. In some embodiments, the thickness of the mass 622 is 1 μm to 50 μm. In some embodiments, the thickness of the mass 622 has a greater influence on the resonance peak (e.g., the second resonance peak) and the sensitivity of the frequency response curve of the sensing device 200. The thicker the mass 622 is, the greater the total mass is, the smaller the second resonance frequency is, the resonance peak (e.g., the second resonance peak) of the sensing device 400 moves forward, and the sensitivity increases.

[0116] In some embodiments, the area of the mass 622 can be within a certain range. In some embodiments, the area of the mass 622 is 0.1 mm 2 to 100 mm 2 . In some embodiments, the area of the mass 622 is 0.1 mm 2 to 50 mm 2 . In some embodiments, the area of the mass 622 is 0.1 mm 2 to 10 mm 2 . In some embodiments, the area of the mass 622 is 0.1 mm 2 to 6 mm 2 . In some embodiments, the area of the mass 622 is 0.1 mm 2 to 3 mm 2 . In some embodiments, the area of the mass 622 is 0.1 mm 2 to 1 mm 2 . In some embodiments, the area of the mass 622 has a greater influence on the resonance peak (e.g., the second resonance peak) and the sensitivity of the frequency response curve of the sensing device 600.

[0117] In some embodiments, to facilitate adjustment of the mechanical parameters of the elastic diaphragm and adjust the stiffness of the resonant system, thereby improving the frequency response of the sensor device and the resonant frequency and sensitivity of the sensor device, the elastic diaphragm may also be a multi-layer composite membrane structure. In some embodiments, the elastic diaphragm may include a multi-layer membrane structure. For example, two layers of the multi-layer composite membrane structure may have different stiffnesses. In another example, three layers of the multi-layer composite membrane structure may have different stiffnesses.

[0118] Figure 7 Schematic diagram of the structure of a sensing device with a multi-layer composite membrane structure and an elastic vibration membrane according to some embodiments of this specification. Figure 6 The structures of the sensor devices 600 shown are substantially the same, with the difference being the elastic vibration membrane. Figure 7 The housing 711, PCB 712, processor 713, sensor element 714, sound inlet 7121, mass block 722, first acoustic cavity 730 and second acoustic cavity 740 are shown in FIG. Figure 6 The structures of the shell 611, PCB 612, processor 613, sensor element 714, sound inlet hole 6121, mass block 622, first acoustic cavity 630 and second acoustic cavity 640 shown are similar and will not be repeated here.

[0119] Further, if Figure 7 As shown, the elastic vibration membrane 721 is a multi-layer composite vibration membrane, which includes a first elastic vibration membrane 7211 and a second elastic vibration membrane 7212. In some embodiments, the first elastic vibration membrane 7211 and the second elastic vibration membrane 7212 can be made of the same or different materials. For example, in some embodiments, the first elastic vibration membrane 7211 and the second elastic vibration membrane 7212 can be made of the same material (for example, polyimide). For another example, in some embodiments, one of the first elastic vibration membrane 7211 and the second elastic vibration membrane 7212 can be made of a polymer material, and the other can be made of another polymer material or a metal material. In some embodiments, the stiffness of the first elastic vibration membrane 7211 and the second elastic vibration membrane 7212 is different. For example, the stiffness of the first elastic vibration membrane 7211 can be greater than or less than the stiffness of the second elastic vibration membrane 7212. In this embodiment, taking the example that the stiffness of the first elastic vibration membrane 7211 is greater than that of the second elastic vibration membrane 7212, the second elastic vibration membrane 7212 can provide the required damping for the resonance system, and the first elastic vibration membrane 7211 has a higher stiffness, which can ensure that the elastic vibration membrane 621 has a higher strength, thereby ensuring the reliability of the resonance system and even the entire sensing device 700.

[0120] It should be noted that Figure 7The number of layers of the membrane structure in the elastic vibrating membrane in the related description is only used for exemplary description, and cannot limit the scope of the embodiments. In some embodiments, the elastic vibrating membrane in the embodiments can also include more than two layers of membrane structures, for example, the number of membrane structures can be three, four, five or more. For example, the elastic vibrating membrane can include a first elastic vibrating membrane, a second elastic vibrating membrane and a third elastic vibrating membrane connected in order from top to bottom, wherein the material, mechanical parameters and size of the first elastic vibrating membrane can be the same as those of the third elastic vibrating membrane, and the material, mechanical parameters and size of the second elastic vibrating membrane can be different from those of the first elastic vibrating membrane or the third elastic vibrating membrane. For example, the rigidity of the first elastic vibrating membrane or the third elastic vibrating membrane is greater than that of the second elastic vibrating membrane. In some embodiments, the mechanical parameters of the elastic vibrating membrane can be adjusted by adjusting the material, mechanical parameters and size of the first elastic vibrating membrane, the second elastic vibrating membrane and / or the third elastic vibrating membrane, so as to ensure the stability of the sensing device 700.

[0121] By setting the elastic vibrating membrane 721 as a multi-layer elastic vibrating membrane, the rigidity adjustment of the elastic vibrating membrane 721 can be facilitated. For example, the rigidity and damping of the resonant system can be adjusted by increasing or reducing the number of elastic vibrating membranes (for example, the first elastic vibrating membrane 7211 and / or the second elastic vibrating membrane 7212), so as to adjust the second resonant frequency, and then a new resonant peak of the sensing device in a required frequency band (for example, near the second resonant frequency) can be generated, and the sensitivity of the sensing device in a specific frequency band can be improved. In some embodiments, the adjacent two layers of membrane structures (for example, the first elastic vibrating membrane 7211 and the second elastic vibrating membrane 7212) in the multi-layer composite membrane structure can be formed by gluing to form the elastic vibrating membrane 721.

[0122] In some embodiments, the rigidity of the elastic vibrating membrane 721 can be adjusted by adjusting the mechanical parameters (for example, material, Young's modulus, tensile strength, elongation and hardness shore A) of the elastic vibrating membranes (the first elastic vibrating membrane 7211 and / or the second elastic vibrating membrane 7212) in the elastic vibrating membrane 721, so that the sensing device 700 has a more ideal frequency response, and the resonant frequency and sensitivity of the sensing device 700 can be adjusted. In some embodiments, in order to improve the sensitivity of the sensing device 700 relative to the sensing structure 710, the second resonant frequency provided by the resonant system can be lower than the first resonant frequency of the sensing structure 710. For example, the second resonant frequency is 1000 Hz-10000 Hz lower than the first resonant frequency, and the sensitivity of the sensing device 700 can be improved by 3 dB-30 dB compared with the sensing structure 710.

[0123] In some embodiments, one of the elastic vibration membranes 721 can be made of a flexible polymer material, which can include but is not limited to polyimide (PI), parylene, polydimethylsiloxane (Pdms), hydrogel, etc., and the other one of the elastic vibration membranes 721 can be made of an inorganic rigid material, which can include but is not limited to semiconductor materials such as silicon (Si) and silicon dioxide (SiO2), or metal materials such as copper, aluminum, steel, and gold.

[0124] In some embodiments, the sensitivity of the sensing device 700 in a specific frequency range can be improved by adjusting the tensile strength of the elastic vibration membranes 721 so that the overall tensile strength of the elastic vibration membranes 721 is within a certain range. In some embodiments, the tensile strength of the elastic vibration membranes 721 as a whole can be adjusted to be 0.5 MPa-100 MPa by adjusting the material, thickness, or size of the first elastic vibration membrane 7211 and / or the second elastic vibration membrane 7212 of the elastic vibration membranes 721. In some embodiments, the tensile strength of the elastic vibration membranes 721 as a whole can be adjusted to be 5 MPa-90 MPa by adjusting the material or size of the first elastic vibration membrane 7211 and / or the second elastic vibration membrane 7212 of the elastic vibration membranes 721. In some embodiments, the tensile strength of the elastic vibration membranes 721 as a whole can be adjusted to be 10 MPa-80 MPa by adjusting the material or size of the first elastic vibration membrane 7211 and / or the second elastic vibration membrane 7212 of the elastic vibration membranes 721. In some embodiments, the tensile strength of the elastic vibration membranes 721 as a whole can be adjusted to be 20 MPa-70 MPa by adjusting the material or size of the first elastic vibration membrane 7211 and / or the second elastic vibration membrane 7212 of the elastic vibration membranes 721. In some embodiments, the tensile strength of the elastic vibration membranes 721 as a whole can be adjusted to be 30 MPa-60 MPa by adjusting the material, thickness, or size of the first elastic vibration membrane 7211 and / or the second elastic vibration membrane 7212 of the elastic vibration membranes 721.

[0125] In some embodiments, the sensitivity of the sensing device 700 in a specific frequency range can be improved by adjusting the elongation of the elastic vibration membranes in the elastic vibration membranes 721 so that the overall elongation of the elastic vibration membranes 721 is within a certain range. In some embodiments, the greater the elongation of the elastic vibration membranes in the elastic vibration membranes 721, the higher the sensitivity of the sensing device 700 and the better the stability. In some embodiments, the overall elongation of the elastic vibration membranes 721 can be 10% to 600%. In some embodiments, the overall elongation of the elastic vibration membranes 721 can be 20% to 500%. In some embodiments, the overall elongation of the elastic vibration membranes 721 can be 50% to 400%. In some embodiments, the overall elongation of the elastic vibration membranes 721 can be 80% to 200%.

[0126] In some embodiments, the sensitivity of the sensing device 700 in a specific frequency range can be improved by adjusting the hardness of the elastic vibration membranes in the elastic vibration membranes 721 so that the overall hardness of the elastic vibration membranes 721 is within a certain range. In some embodiments, the smaller the hardness of the elastic vibration membranes in the elastic vibration membranes 721, the higher the sensitivity of the sensing device 700. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 200 Shore A. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 150 Shore A. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 100 Shore A. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 60 Shore A. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 30 Shore A. In some embodiments, the overall hardness of the elastic vibration membranes 721 is less than 10 Shore A.

[0127] In some embodiments, the sensitivity of the sensing device 700 can also be adjusted by adjusting the mechanical parameters (e.g., material, size, shape, etc.) of the mass 722. For how to adjust the mechanical parameters of the mass 722 to achieve the adjustment of the sensitivity of the sensing device 700, please refer to the related description in the Figure 6 about adjusting the mechanical parameters of the mass 622 to achieve the adjustment of the sensitivity of the sensing device 600.

[0128] In some embodiments, when the parameters (e.g., Young's modulus, tensile strength, hardness, elongation, etc.) of the elastic vibration membranes and the volume or mass of the mass are certain, the efficiency of the elastic deformation of the elastic vibration membranes can be improved to increase the electrical signal output by the sensing device, thereby improving the acoustoelectric conversion effect of the sensing device. In some embodiments, the area of the mass in contact with the elastic vibration membranes can be reduced to improve the efficiency of the elastic deformation of the elastic vibration membranes, thereby increasing the electrical signal output by the sensing device.

[0129] Figure 8 is a structural schematic diagram of a sensing device provided according to some embodiments of the present specification. The structure of the sensing device 800 is substantially the same as that of the sensing device 600 shown in Figure 6 , with the difference being the mass. Among them, Figure 7 the structure of the housing 811, the PCB 812, the processor 813, the sensing element 814, the sound inlet hole 8121, the elastic diaphragm 821, the first acoustic cavity 830, the second acoustic cavity 840 and the like are respectively similar to the structure of the housing 611, the PCB 612, the processor 613, the sensing element 714, the sound inlet hole 6121, the elastic diaphragm 621, the first acoustic cavity 630, the second acoustic cavity 640 and the like shown in Figure 8 , and the structure of the elastic diaphragm 821 can also be similar to the structure of the elastic diaphragm 721 in the sensing device 700 shown in Figure 6 , which will not be described here in detail. Figure 7

[0130] As shown in Figure 8 ​As shown, the mass 822 can be an ellipsoidal ball, and the contact area of the mass 822 with the elastic vibrating membrane 821 is less than the projected area of the mass 822 on the elastic vibrating membrane 821. In this way, the mass 822 can have a smaller contact area with the elastic vibrating membrane 821 under the same volume or mass, and the contact area of the elastic vibrating membrane 821 with the mass 822 can be approximately considered as not deformed when the housing 110 of the sensing device vibrates to drive the mass 822 to vibrate. By reducing the contact area of the elastic vibrating membrane 821 with the mass 822, the area of the region of the elastic vibrating membrane 821 not in contact with the mass 822 can be increased, thereby increasing the area of the region of the elastic vibrating membrane 821 deformed during vibration (i.e., the area of the region of the elastic vibrating membrane 821 not in contact with the mass 822), so that the amount of air compressed in the first acoustic cavity 830 can be increased, and the sensing element 814 of the sensing structure 810 can output a larger electrical signal, thereby improving the acoustoelectric conversion effect of the sensing device 800. In some embodiments, the mass 822 can also be a trapezoidal body, and the smaller side of the trapezoidal body is connected to the elastic vibrating membrane 821. In this way, the contact area of the mass 822 with the elastic vibrating membrane 821 can be less than the projected area of the mass 822 on the elastic vibrating membrane 821. In some embodiments, the mass 822 can also be an arch structure, and two arch feet of the arch structure are connected to the upper surface or the lower surface of the elastic vibrating membrane 821, and the contact area of the two arch feet with the elastic vibrating membrane 821 is less than the projected area of the arch waist on the elastic vibrating membrane 821, i.e., the contact area of the mass 822 of the arch structure with the elastic vibrating membrane 821 is less than the projected area of the mass 822 on the elastic vibrating membrane 821. It should be noted that any regular or irregular shape or structure that can satisfy the condition that the contact area of the mass 822 with the elastic vibrating membrane 821 is less than the projected area of the mass 822 on the elastic vibrating membrane 821 belongs to the range of variations of the embodiments of the present specification, and the present specification will not be listed one by one.

[0131] In some embodiments, the mass can be a solid structure. For example, the mass 822 can be a solid cylinder, a solid cuboid, a solid ellipsoidal ball, a solid triangular body, or the like regular or irregular structure. In some embodiments, in order to ensure that the mass 822 reduces the contact area with the elastic vibrating membrane 821 under the same mass and improves the sensitivity of the sensing device in a specific frequency range, the mass can also be a partially hollow structure. For example, as shown in FIG. 8B, the mass 822 is a hollow cylinder. Figure 9 For another example, as shown in FIG. 8C, the mass 822 is a hollow rectangular cylinder. Figure 10 For another example, as shown in FIG. 8D, the mass 822 is a hollow rectangular cylinder.

[0132] In some embodiments, the mass block may include multiple, mutually separated sub-masses, with the multiple sub-masses located in different regions of the elastic diaphragm. In some embodiments, the mass block may include two or more mutually separated sub-masses, for example, three, four, or five. In some embodiments, the mass, size, shape, and material of the multiple mutually separated sub-masses may be the same or different. In some embodiments, the multiple mutually separated sub-masses may be distributed with equal spacing, unequal spacing, symmetrical distribution, or asymmetrical distribution on the elastic diaphragm. In some embodiments, the multiple mutually separated sub-masses may be disposed on the upper and / or lower surface of the elastic diaphragm. By disposing multiple mutually separated sub-masses in the central region of the elastic diaphragm, not only can the deformation area of ​​the elastic diaphragm under vibration driven by the housing be increased, thereby improving the deformation efficiency of the elastic diaphragm and thereby enhancing the sensitivity of the sensing device, but also the reliability of the resonant system and the sensing device can be improved. In some embodiments, the mass, size, shape, material, and other parameters of the multiple mass blocks can be adjusted to provide the multiple sub-masses with different frequency responses, thereby further improving the sensitivity of the sensing device within different frequency bands.

[0133] Figure 11 Schematic diagram of a cross section of a sensor device according to some embodiments of this specification. Figure 11 As shown, mass 1122 may include two rectangular cylindrical sub-masses 1122a and 1122b having dimensions in a certain ratio. In some embodiments, the thickness (i.e., the wall thickness) of sub-mass 1122a and sub-mass 1122b is the same. In some embodiments, the length and width of sub-mass 1122a are respectively the same as the ratio of the length and width of sub-mass 1122b. In some embodiments, the length and / or width ratio of sub-mass 1122a to sub-mass 1122b is in a range of 0.1 to 0.8. In some embodiments, the length and / or width ratio of sub-mass 1122a to sub-mass 1122b is in a range of 0.2 to 0.6. In some embodiments, the length and / or width ratio of sub-mass 1122a to sub-mass b is in a range of 0.25 to 0.5. In some embodiments, the two rectangular cylindrical sub-masses 1122a and 1122b are both located in the middle region of the elastic vibration membrane 1121, and their geometric centers coincide with the geometric center of the elastic vibration membrane 1121. In some embodiments, the geometric centers of the rectangular cylindrical sub-masses 1122a and 1122b may not coincide.

[0134] It should be noted that the number of sub-masses is not limited to Figure 11 The two mentioned above can also be three, four or more. In addition, the shape of the sub-mass block is not limited to Figure 11The rectangular cylinder shown can also be other shaped structures. For example, in some embodiments, the mass 1122 can include two annular sub-masses with different inner diameters, both of which are located in the middle region of the elastic diaphragm 1121 and have their centers of the circles coincide with the geometric center of the elastic diaphragm 1121. For another example, the mass 1122 can include two sub-masses with different shapes (e.g., an annular sub-mass and a rectangular sub-mass), with the larger sub-mass surrounding the smaller sub-mass. In addition, multiple sub-masses can be located on different surfaces of the elastic diaphragm 1121, for example, one part on the upper surface of the elastic diaphragm 1121 and another part on the lower surface of the elastic diaphragm 1121.

[0135] Figure 12 is a cross-sectional schematic view of a sensing device provided according to some embodiments of the present specification. As shown in Figure 12 , the mass 1222 can include four sub-masses 1222c, 1222d, 1222e, 1222f, which are arranged in a matrix in the middle region of the elastic diaphragm 1221. Among them, the sub-masses 1222c, 1222d, 1222e, 1222f can have any regular or irregular shape such as a rectangle, a circle, an ellipse, etc. In some embodiments, the shapes, sizes, materials, etc. of the sub-masses 1222c, 1222d, 1222e, 1222f can be the same or different.

[0136] Figure 13 is a cross-sectional schematic view of a sensing device provided according to some embodiments of the present specification. As shown in Figure 13 , the mass 1322 can include four sub-masses 1322g, 1322h, 1322i, 1222j, which are arranged in a ring on the middle region of the elastic diaphragm 1321 at equal intervals, and the center of the ring coincides with the geometric center of the elastic diaphragm 1321.

[0137] It should be noted that Figures 11-13 the number, shape, and distribution of the sub-masses shown are only for exemplary description and are not intended to limit the present specification. For example, Figure 11 the rectangular cylinder sub-mass in Figure 13 the number of sub-masses in Figure 12 may be more than two (e.g., 3, 4, 5, etc.). For another example, the number of sub-masses in

[0138] may be 6 arranged in a 2x3 matrix or 8 arranged in a 4x4 matrix, etc. Figures 9-13The sensing devices 900, 1000, 1100, 1200, and 1300 shown in FIGS. 9-13, respectively, are substantially the same in structure as the sensing devices 600, 700, or 800 shown in FIGS. 6-8, respectively, and differ from the sensing devices 600, 700, or 800 in that the mass blocks are different. Figures 6-8 The sensing devices 900, 1000, 1100, 1200, and 1300 shown in FIGS. 9-13, respectively, are substantially the same in structure as the sensing devices 600, 700, or 800 shown in FIGS. 6-8, respectively, and differ from the sensing devices 600, 700, or 800 in that the mass blocks are different. Figures 9-13 The descriptions of the housings 911, 1011, 1111, 1211, and 1311 and the elastic vibration membranes 921, 1021, 1121, 1221, and 1321 shown in FIGS. 9-13, respectively, can refer to the related descriptions of the housings and the elastic vibration membranes in the foregoing embodiments. Figures 6-8 The descriptions of the housings 911, 1011, 1111, 1211, and 1311 and the elastic vibration membranes 921, 1021, 1121, 1221, and 1321 shown in FIGS. 9-13, respectively, can refer to the related descriptions of the housings and the elastic vibration membranes in the foregoing embodiments.

[0139] Exemplarily, Figure 14 is a structural schematic diagram of a sensing device provided according to some embodiments of the present specification. Figure 14 The sensing device 1400 shown in FIG. 14 is substantially the same in structure as the sensing device 600 shown in FIG. 6, and differs from the sensing device 600 in that the elastic vibration membrane is different. Figures 6-13 The sensing devices 600, 700, 800, 900, 1000, 1100, 1200, and 1300 shown in FIGS. 6-13, respectively, can be substantially the same in structure, and differ from each other in that the areas of the elastic vibration membranes are different. Therefore, the descriptions of the housings, the PCBs, the processors, the sensing elements, the sound inlet holes, the mass blocks, the first acoustic cavities, the second acoustic cavities, and the like in the foregoing embodiments can refer to the related descriptions of the housings, the PCBs, the processors, the sensing elements, the sound inlet holes, the mass blocks, the first acoustic cavities, the second acoustic cavities, and the like in the foregoing embodiments, and will not be repeated here. Figure 14 The descriptions of the housings 1411, the PCB 1412, the processor 1413, the sensing element 1414, the sound inlet hole 14121, the mass block 1422, the first acoustic cavity 1430, the second acoustic cavity 1440, and the like shown in FIG. 14 can refer to the related descriptions of the housings, the PCBs, the processors, the sensing elements, the sound inlet holes, the mass blocks, the first acoustic cavities, the second acoustic cavities, and the like in the foregoing embodiments. Figures 6-13 The descriptions of the housings 1411, the PCB 1412, the processor 1413, the sensing element 1414, the sound inlet hole 14121, the mass block 1422, the first acoustic cavity 1430, the second acoustic cavity 1440, and the like shown in FIG. 14 can refer to the related descriptions of the housings, the PCBs, the processors, the sensing elements, the sound inlet holes, the mass blocks, the first acoustic cavities, the second acoustic cavities, and the like in the foregoing embodiments.

[0140] Figure 14 The area of the elastic vibration membrane 1421 of the sensing device 1400 shown in FIG. 14 is smaller than the area of the PCB, and the elastic vibration membrane is located at a position opposite to the sound inlet hole. Correspondingly, the part of the elastic vibration membrane connected to the housing 1410 is adapted to the size of the elastic vibration membrane. By such arrangement, the area of the elastic vibration membrane 1421 in the horizontal direction is reduced, i.e., the area of the first acoustic cavity 1430 in the horizontal direction is also reduced, and the space volume of the first acoustic cavity 1430 is reduced, so that the sensitivity of the sensing device 1400 in a specific frequency range can be improved.

[0141] Figure 15 is a structural schematic diagram of a sensing device provided according to some embodiments of the present specification. Figure 15 The sensing device 1500 shown in FIG. 15 is substantially the same in structure as the sensing device 600 shown in FIG. 6, and differs from the sensing device 600 in that the elastic vibration membrane is different. Figure 6 The sensing device 1500 shown in FIG. 15 is substantially the same in structure as the sensing device 600 shown in FIG. 6, and differs from the sensing device 600 in that the elastic vibration membrane is different. Figure 15 The elastic vibration membrane 1521 shown in FIG. 15 is provided with a first hole part 15211.Figure 15 The structures shown in FIG. 15A, such as the housing 1511, the PCB 1512, the processor 1513, the sensing element 1514, the sound inlet hole 15121, the mass block 1522, the first acoustic cavity 1530, and the second acoustic cavity 1540, are similar to those in FIG. 1A, and are not described here again. Figure 6 The structures shown in FIG. 16A, such as the middle housing 611, the PCB 612, the processor 613, the sensing element 614, the sound inlet hole 6121, the mass block 622, the first acoustic cavity 630, and the second acoustic cavity 640, are similar to those in FIG. 1A, and are not described here again.

[0142] In some embodiments, as shown in FIG. 15A, one or more first hole portions 15211 can be included on the elastic diaphragm 1521. The first hole portions 15211 can be in communication with the first acoustic cavity 1530 and the second acoustic cavity 1540, to adjust the air pressure in the first acoustic cavity 1530 and the second acoustic cavity 1540, balance the air pressure difference in the two cavities, prevent damage to the sensing device 1500, and also increase the damping of the resonant system, reduce the quality factor Q value of the sensing device 1500, and make the frequency response curve of the sensing device 1500 more flat. The second acoustic cavity 1540 can refer to a cavity formed between the elastic diaphragm 1521 and the housing 1511, which is different from the first acoustic cavity 1530. Figure 15

[0143] Figure 16 is a cross-sectional view of a sensing device according to some embodiments of the present disclosure. Figure 15 is a cross-sectional view of a sensing device according to some embodiments of the present disclosure. Figure 16 In some embodiments, as shown in FIG. 15A, the first hole portions 15211 can be located in the area of the elastic diaphragm 1521 that is not covered by the mass block 1522. In some embodiments, the number of first hole portions 15211 on the elastic diaphragm 1521 can be set according to the actual required damping, for example, the number of first hole portions 15211 can be 4, 8, 16, etc. In some embodiments, the plurality of first hole portions 15211 can be distributed in a rectangular or ring-shaped manner at equal intervals in the area of the elastic diaphragm 1521 that is not covered by the mass block 1522.

[0144] In some embodiments, the mass block can include one or more second hole portions in communication with the first hole portions, to adjust the air pressure in the first acoustic cavity and the second acoustic cavity, and also adjust the damping of the resonant system, so that the frequency response curve of the sensing device is more flat.

[0145] Figure 17 is a cross-sectional view of a sensing device according to some embodiments of the present disclosure. Figure 17 The sensing device 1700 shown in FIG. 17A is substantially the same in structure as the sensing device 1500 shown in FIG. 15A, and the difference is that Figure 15 or Figure 16 The sensing device 1700 shown in FIG. 17A is substantially the same in structure as the sensing device 1500 shown in FIG. 15A, and the difference is that Figure 17 ​The mass block 1722 of the sensor device 1700 is provided with a second hole portion 17221. Figure 17 The description of the housing 1711 and the elastic vibration membrane 1721 can refer to Figure 15 or Figure 16 (or Figures 6-14 ) for the relevant description of the shell and elastic vibration membrane.

[0146] In some embodiments, as Figure 17 As shown, the mass block 1722 is provided with a plurality of second holes 17221, and the elastic vibration membrane 621 is provided with a plurality of first holes 17211. Some of the first holes 17211 are located in the area of ​​the elastic vibration membrane 1721 covered by the mass block 1722, and correspond in position to the second holes 17221. The first holes 17211 located in the area of ​​the elastic vibration membrane 1721 covered by the mass block 1722 can communicate with the corresponding second holes 17221, thereby ensuring communication between the first acoustic cavity 1730 and the second acoustic cavity 1740. Furthermore, another portion of the first holes 17211 is located in the area of ​​the elastic vibration membrane 1721 not covered by the mass block 1722, thereby also achieving communication between the first acoustic cavity 1730 and the second acoustic cavity 1740.

[0147] In some embodiments, the first hole portion (e.g., Figure 15 The first hole portion 15211 or Figure 17 The pore size of the first or second hole portion 17211 or 17221 shown is 0.01 μm to 40 μm. In some embodiments, the pore size of the first or second hole portion 17221 is 0.03 μm to 30 μm. In some embodiments, the pore size of the first or second hole portion 17221 is 0.05 μm to 20 μm.

[0148] In some embodiments, rather than providing a first hole in the elastic diaphragm or a second hole in the mass, the elastic diaphragm can be manufactured using a thin film material containing micropores. In this embodiment, the micropores of the elastic diaphragm can serve as gas conduction, regulating the air pressure within the acoustic cavity and adjusting the damping of the resonant system.

[0149] In the present embodiment, the elastic diaphragm can be made of a microporous film of polytetrafluoroethylene (PTFE), nylon, polyether sulphone (PES), polyvinylidene fluoride (PVDF), polypropylene (PP), or the like. Preferably, the elastic diaphragm can be made of a PTFE microporous film. In some embodiments, the microporous film has a micropore diameter of 0.01 μm to 10 μm. In some embodiments, the microporous film has a micropore diameter of 0.05 μm to 10 μm. In some embodiments, the microporous film has a micropore diameter of 0.1 μm to 10 μm. The use of a microporous film for the elastic diaphragm can eliminate the need for perforating the elastic diaphragm or the mass, thus simplifying the manufacturing process and saving cost.

[0150] In some embodiments, the elastic diaphragm can further include an elastic layer or layers (not shown in the figures), which can be located in the area of the elastic diaphragm not covered by the mass. The elastic layer can cover at least part of the first hole portion or the micropores of the elastic diaphragm, which can adjust the porosity of the first hole portion or the micropores, and can also adjust the stiffness of the elastic diaphragm, thus adjusting the sensitivity and reliability of the sensing device 200. In some embodiments, the material of the elastic layer can be silicone gel, silica gel, or the like. In some embodiments, the thickness of the elastic layer can be 0.1 μm to 500 μm. In some embodiments, the thickness of the elastic layer can be 0.5 μm to 300 μm. In some embodiments, the thickness of the elastic layer can be 1 μm to 100 μm. In some embodiments, the thickness of the elastic layer can be 50 μm to 100 μm.

[0151] In some embodiments, a filler with fluidity can be provided in a second acoustic cavity (e.g., the second acoustic cavity 640, 740, 840, etc.) in the sensing device, which is different from the first acoustic cavity (e.g., the first acoustic cavity 630, 730, 830, etc.). Figures 6-8 In some embodiments, a filler with fluidity can be provided in a second acoustic cavity (e.g., the second acoustic cavity 640, 740, 840, etc.) in the sensing device, which is different from the first acoustic cavity (e.g., the first acoustic cavity 630, 730, 830, etc.). Figures 6-8 In some embodiments, a filler with fluidity can be provided in a second acoustic cavity (e.g., the second acoustic cavity 640, 740, 840, etc.) in the sensing device, which is different from the first acoustic cavity (e.g., the first acoustic cavity 630, 730, 830, etc.). Figure 6Taking the sensor device 600 shown as an example, the second acoustic cavity 240 can be the cavity formed between the elastic diaphragm 621 and / or mass 622 and the housing 611 of the sensor structure. By placing a fluid-conductive filler within the second acoustic cavity 640, the quality factor (Q) and sensitivity of the sensor device 600 can be adjusted. Furthermore, when the sensor device 600 is impacted, the fluid filler can absorb the impact load, preventing damage to the sensor device 600. In some embodiments, the greater the kinematic viscosity of the filler, the higher the sensitivity of the sensor device 600. In some embodiments, the kinematic viscosity of the filler is within 20,000 cSt. In some embodiments, the kinematic viscosity of the filler is within 10,000 cSt. In some embodiments, the kinematic viscosity of the filler is within 5,000 cSt. In some embodiments, the kinematic viscosity of the filler is within 500 cSt. In some embodiments, the kinematic viscosity of the filler is within 50 cSt. In some embodiments, the kinematic viscosity of the filler is within 50 cSt. In some embodiments, the fluid filler within the second acoustic cavity 640 can comprise a flexible material such as a liquid, a gas, or a gel. Preferably, the material of the fluid filler in the second acoustic cavity 640 is oil, aloe vera gel, silicone gel, polydimethylsiloxane (PDMS), etc. In some embodiments, the fluid filler can completely fill the second acoustic cavity 640 or partially fill it (for example, with bubbles).

[0152] In some embodiments, the sensing device may include multiple resonance systems, which may enable multi-modal vibration of the sensing device and improve the sensitivity of the sensing device in a wider frequency range.

[0153] Figure 18 FIG. 1 is a schematic diagram of a structure of a sensing device including multiple resonant systems according to some embodiments of this specification. Figure 18 As shown, the sensing device 1900 includes a sensing structure 1910, a first resonance system, and a second resonance system. In some embodiments, the first resonance system includes a first vibration pickup unit 1920 and a second vibration pickup unit 1930, wherein the first vibration pickup unit 1920 may include a first elastic vibration membrane 1921 and a first mass block 1922, and the second vibration pickup unit 1930 may include a second elastic vibration membrane 1931 and a second mass block 1932. In some embodiments, the sensing structure 1910 may include a housing 1911, a printed circuit board (PCB) 1912, a processor 1913, and a sensing element 1914. For details about the housing 1911, PCB 1912, processor 1913, and sensing element 1914, please refer to this specification. Figure 1B The description of the printed circuit board (PCB) 141, the housing 142, the sensor element 143 and the processor 144 or Figure 6The related descriptions about the shell 611, the PCB 611, the sensing element 614, and the processor 613 are not repeated here. In addition, the first elastic diaphragm 1921 and the second elastic diaphragm 1931, the first mass 1922 and the second mass 1932 in this embodiment are similar to (for example, have the same material, structure, shape, size, stiffness, damping, and other mechanical parameters) the elastic diaphragm and the mass in other embodiments of the present specification, and therefore, more details of the first elastic diaphragm 1921 and the second elastic diaphragm 1931, the first mass 1922 and the second mass 1932 in this embodiment can be referred to other places in the present specification, for example Figures 6-18 The related descriptions about the elastic diaphragm and the mass.

[0154] Further, the first elastic diaphragm 1921 is connected to the shell 1911 by the periphery thereof, the second elastic diaphragm 1931 is connected to the shell 1911 by the periphery thereof, and the first elastic diaphragm 1921 and the second elastic diaphragm 1931 are arranged in sequence from top to bottom. In this embodiment, the first resonant system can provide a third resonant frequency, and the second resonant system can provide a fourth resonant frequency. When the shell 1911 of the sensing device 1900 vibrates due to an external signal, the first resonant system and the second resonant system are simultaneously driven to vibrate, so as to cause air vibration in the cavities (i.e., the third acoustic cavity 1940) formed between the first elastic diaphragm 1921 and the second elastic diaphragm 1931, the cavities (i.e., the fourth acoustic cavity 1950) formed between the first elastic diaphragm 1921 and the sensing structure 1910, and the cavities (i.e., the fifth acoustic cavity 1960) formed between the second elastic diaphragm 1931 and the shell 1911, and cause the sound pressure in the third acoustic cavity 1940, the fourth acoustic cavity 1950, and the fifth acoustic cavity 1960 to change. In some embodiments, the first elastic diaphragm 1921 and the second elastic diaphragm 1931 can be microporous films or film structures having holes (for example, the first hole 15211 or the second hole 17211 shown in the drawings), so that the sound pressure changes in the third acoustic cavity 1940, the fourth acoustic cavity 1950, and the fifth acoustic cavity 1960 can be transmitted to the sensing element 1914 through the holes. Figures 15-17 The first vibration pickup unit 1920 and the second vibration pickup unit 1930 have different frequency responses, and by arranging two or more resonant systems, multi-modal vibration of the sensing device 1900 can be achieved, and the sensitivity of the sensing device in a wider frequency range can be improved.

[0155] In some embodiments, the third resonant frequency of the first resonant system and the fourth resonant frequency of the second resonant system are different by adjusting the mechanical parameters (e.g., mass, material, shape, size, stiffness, damping, etc.) of the components (e.g., the first elastic diaphragm 1921, the second elastic diaphragm 1931, the first mass 1922, and the second mass 1932) of the first resonant system and the second resonant system. In some embodiments, the difference between the third resonant frequency and the fourth resonant frequency can be less than 2000 Hz. In some embodiments, the difference between the third resonant frequency and the fourth resonant frequency is less than 1000 Hz. In some embodiments, the difference between the third resonant frequency and the fourth resonant frequency is less than 800 Hz. In some embodiments, the difference between the third resonant frequency and the fourth resonant frequency is less than 500 Hz.

[0156] It should be noted that, Figure 18 The number of resonant systems in the above description is only for exemplary description, and does not constitute a limitation. In some embodiments, the number of resonant systems in the sensing device can be more than two, for example, the sensing device can further include a third resonant system, a fourth resonant system, etc. Wherein, when the sensing device includes multiple resonant systems, the elastic diaphragm in each resonant system can be a membrane structure with a hole or a microporous film, so as to be able to transmit the sound pressure change in each cavity to the sensing element. The multiple resonant systems have different frequency responses, and by setting two or more resonant systems, the multi-modal vibration of the sensing device can be realized, and the sensitivity of the sensing device in a wider frequency range can be improved.

[0157] By setting the sensing device to include multiple resonant systems, the frequency response curve of the sensing device can produce new resonant peaks in multiple frequency bands (e.g., near the third resonant frequency or near the fourth resonant frequency), thereby improving the sensitivity of the sensing device in a specific frequency band range, and the frequency range corresponding to the high sensitivity of the sensing device can be expanded.

[0158] The above has described the basic concept, and it is obvious that the above detailed disclosure is only an example and does not constitute a limitation on the present application. Although it is not explicitly stated here, those skilled in the art can make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

Claims

1. A sensing device, characterized by The shell is configured to convert a sound signal into vibration; a sensing structure for converting the sound signal into an electrical signal; and a resonant system, the resonant system comprising a pick-up unit, the pick-up unit comprising an elastic diaphragm connected with the shell and a mass block, a mass of a high polymer material in the mass block exceeding 80%; the elastic diaphragm and the sensing structure form a first acoustic cavity, when the shell vibrates, the elastic diaphragm and the mass block generate vibration in response to the vibration of the shell, the vibration of the elastic diaphragm causes the acoustic pressure of the first acoustic cavity to change, and the sensing structure converts the change of the acoustic pressure of the acoustic cavity into an electrical signal; a frequency response curve of the sensing device comprises at least two resonance peaks, the at least two resonance peaks comprising a first resonance peak and a second resonance peak, the first resonance peak being a resonance peak corresponding to the sensing structure, the second resonance peak being a resonance peak generated by the action of the resonant system, the resonance frequency corresponding to the first resonance peak being a first resonance frequency, the resonance frequency corresponding to the second resonance peak being a second resonance frequency, the second resonance frequency being lower than the first resonance frequency, and the resonant system being configured to suppress a difference between a peak value of a highest peak and a valley value of a lowest valley of the frequency response curve between the first resonance frequency and the second resonance frequency not exceeding 30 dBV. The mass of the high polymer material in the elastic diaphragm exceeds 80%.

2. The sensing device of claim 1, wherein, The elastic diaphragm and the mass block are made of the same material.

3. The sensing device of claim 2, wherein, The Young's modulus of the elastic diaphragm is 1 MPa to 10 GPa.

4. The sensing device of claim 1, wherein, The tensile strength of the elastic diaphragm is 0.5 MPa to 100 MPa.

5. The sensing device of claim 1, wherein, The elongation of the elastic diaphragm is 10% to 600%.

6. The sensing device of claim 1, wherein, The hardness shore A of the elastic diaphragm is less than 200.

7. The sensing device of claim 1, wherein, The elastic diaphragm is a multi-layer composite membrane structure.

8. The sensing device according to any one of claims 4-7, characterized in that, The stiffness of two membrane structures in the multi-layer composite membrane structure is different.

9. The sensing device of claim 8, wherein, The area of the mass block in contact with the elastic diaphragm is less than the projection area of the mass block on the elastic diaphragm.

10. The sensing device of claim 1, wherein, The mass block comprises a plurality of mutually separated sub-mass blocks, and the plurality of sub-mass blocks are distributed in different areas of the elastic diaphragm.

11. The sensing device of claim 1, wherein, The elastic diaphragm separates the cavity inside the shell into the first acoustic cavity and the second acoustic cavity, and the elastic diaphragm comprises a first hole part, the first hole part communicating the first acoustic cavity and the second acoustic cavity.

12. The sensing device of claim 1, wherein, The first hole part is located in the area of the elastic diaphragm not covered by the mass block.

13. The sensing device of claim 12, wherein, The mass block comprises a second hole part, and the second hole part communicates with the first hole part.

14. The sensing device of claim 12, wherein, The aperture of the first hole part or the second hole part is 0.01 μm to 40 μm.

15. The sensing device of claim 14, wherein, ​

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